diff --git a/.github/workflows/emu-build-all-win.yml b/.github/workflows/emu-build-all-win.yml
index e146d2808..485349f3c 100644
--- a/.github/workflows/emu-build-all-win.yml
+++ b/.github/workflows/emu-build-all-win.yml
@@ -48,7 +48,11 @@ jobs:
       - name: "Checkout branch"
         uses: actions/checkout@v4
         with:
-          clean: false
+          # clean:true so stale generated/build artifacts from prior runs (e.g. a
+          # removed base_gcmessages.pb.* or old steam_api DLLs) can't get compiled,
+          # linked, or shipped. Deps live in C:\gbe-deps (junctioned later), so a
+          # clean checkout doesn't force a deps rebuild.
+          clean: true
 
       - name: "Setup MSBuild"
         uses: microsoft/setup-msbuild@v2
@@ -83,7 +87,11 @@ jobs:
         shell: cmd
         working-directory: "${{ github.workspace }}"
         run: |
-          "${{env.THIRD_PARTY_BASE_DIR}}\common\win\premake\premake5.exe" --file=premake5.lua --genproto --emubuild=${{ github.sha }} --dosstub --winrsrc --winsign --os=windows vs2022
+          rem No --dosstub/--winsign: that post-build tooling (file_dos_stub_x32.exe /
+          rem sign_helper.bat) crashes on the 32-bit DLL and removes the just-linked
+          rem output, and the emu DLLs don't need a replaced DOS stub or a code
+          rem signature to function. Keep --winrsrc (version resource) which is fine.
+          "${{env.THIRD_PARTY_BASE_DIR}}\common\win\premake\premake5.exe" --file=premake5.lua --genproto --emubuild=${{ github.sha }} --winrsrc --os=windows vs2022
 
       - name: "Build all targets"
         shell: cmd
@@ -92,6 +100,11 @@ jobs:
           @echo off
           setlocal enabledelayedexpansion
 
+          rem The build job checks out with clean:false, so stale DLLs from a prior
+          rem build linger. Wipe the release output dir first so a target that fails
+          rem to build this run cannot ship a leftover DLL (false success).
+          if exist "%GITHUB_WORKSPACE%\build\win\vs2022\release" rmdir /s /q "%GITHUB_WORKSPACE%\build\win\vs2022\release"
+
           for %%P in (api_regular api_experimental steamclient_experimental_stub steamclient_experimental steamclient_experimental_loader steamclient_experimental_extra lib_game_overlay_renderer lib_steamnetworkingsockets tool_lobby_connect tool_generate_interfaces) do (
             for %%A in (x64 Win32) do (
               echo === Building %%P [%%A release] ===
@@ -104,6 +117,33 @@ jobs:
           msbuild /nologo /t:lib_steam_old /m /v:m /p:Configuration=release,Platform=Win32 gbe.sln
           if errorlevel 1 echo Warning: lib_steam_old Win32 release build failed
 
+          rem Per-target failures above are warn-only (e.g. signing of a dev-only tool,
+          rem or lib_steam_old). Don't let them abort the job here; the next step gates
+          rem the release on the actual shippable DLLs existing.
+          exit /b 0
+
+      - name: "Verify shippable DLLs built"
+        shell: cmd
+        working-directory: "${{ github.workspace }}"
+        run: |
+          setlocal enabledelayedexpansion
+          set "OUT=%GITHUB_WORKSPACE%\build\win\vs2022\release"
+          set "MISSING="
+          rem premake emits 32-bit to the x86 dir (and 64-bit to x64).
+          for %%F in (
+            "regular\x64\steam_api64.dll"
+            "regular\x86\steam_api.dll"
+            "experimental\x64\steam_api64.dll"
+            "experimental\x86\steam_api.dll"
+          ) do (
+            if exist "%OUT%\%%~F" ( echo OK: %%~F ) else ( echo MISSING: %%~F & set "MISSING=1" )
+          )
+          if defined MISSING (
+            echo One or more shippable steam_api DLLs are missing - failing the build.
+            exit /b 1
+          )
+          echo All shippable steam_api DLLs present.
+
       - name: "Package build (release)"
         shell: cmd
         working-directory: "${{ github.workspace }}"
diff --git a/.github/workflows/emu-deps-win.yml b/.github/workflows/emu-deps-win.yml
index 8cf613082..007d7f6d0 100644
--- a/.github/workflows/emu-deps-win.yml
+++ b/.github/workflows/emu-deps-win.yml
@@ -2,7 +2,19 @@ name: "Emu third-party dependencies (Windows)"
 
 on:
   workflow_call:
+    inputs:
+      force_rebuild:
+        description: "Wipe the local deps cache and rebuild from scratch"
+        required: false
+        type: boolean
+        default: false
   workflow_dispatch:
+    inputs:
+      force_rebuild:
+        description: "Wipe the local deps cache and rebuild from scratch"
+        required: false
+        type: boolean
+        default: false
 
 permissions:
   contents: "write"
@@ -23,12 +35,24 @@ jobs:
         id: "local-deps-check"
         shell: cmd
         run: |
-          if exist "%LOCAL_DEPS_DIR%\vs2022\protobuf\install64" (
+          if /I "${{ inputs.force_rebuild }}"=="true" (
+            echo Force rebuild requested - wiping %LOCAL_DEPS_DIR%\vs2022
+            if exist "%LOCAL_DEPS_DIR%\vs2022" rmdir /s /q "%LOCAL_DEPS_DIR%\vs2022"
+          )
+          rem Require markers from multiple deps, not just protobuf: a partial cache
+          rem (e.g. protobuf present but zlibstatic.lib missing) used to pass this
+          rem check and never refresh, which broke api_regular linking. Treat a
+          rem missing critical lib as "needs rebuild".
+          set DEPS_OK=1
+          if not exist "%LOCAL_DEPS_DIR%\vs2022\protobuf\install64" set DEPS_OK=0
+          if not exist "%LOCAL_DEPS_DIR%\vs2022\zlib\install64\lib\zlibstatic.lib" set DEPS_OK=0
+          if not exist "%LOCAL_DEPS_DIR%\vs2022\sdl\install64\lib\SDL3-static.lib" set DEPS_OK=0
+          if "%DEPS_OK%"=="1" (
             echo deps_exist=true>>%GITHUB_OUTPUT%
-            echo Deps already exist at %LOCAL_DEPS_DIR%
+            echo Deps already exist and look complete at %LOCAL_DEPS_DIR%
           ) else (
             echo deps_exist=false>>%GITHUB_OUTPUT%
-            echo Deps not found, will build
+            echo Deps missing or incomplete, will build
           )
 
       - name: "Checkout branch"
@@ -60,6 +84,14 @@ jobs:
           ref: "third-party/deps/common"
           path: "${{env.THIRD_PARTY_BASE_DIR}}/deps/common"
 
+      - name: "Enable long paths (best-effort)"
+        if: steps.local-deps-check.outputs.deps_exist != 'true'
+        shell: cmd
+        run: |
+          rem Deeply nested dep build paths (abseil etc.) can exceed Windows' 260-char
+          rem MAX_PATH. Best-effort enable long paths; ignore failure if not admin.
+          reg add "HKLM\SYSTEM\CurrentControlSet\Control\FileSystem" /v LongPathsEnabled /t REG_DWORD /d 1 /f || ver > nul
+
       - name: "Build deps"
         if: steps.local-deps-check.outputs.deps_exist != 'true'
         shell: cmd
diff --git a/dll/steam_client_interface_getter.cpp b/dll/steam_client_interface_getter.cpp
index cdde57ebb..686be092d 100644
--- a/dll/steam_client_interface_getter.cpp
+++ b/dll/steam_client_interface_getter.cpp
@@ -30,7 +30,8 @@ ISteamBilling *Steam_Client::GetISteamBilling( HSteamUser hSteamUser, HSteamPipe
         return reinterpret_cast<ISteamBilling *>(static_cast<ISteamBilling *>(steam_billing));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 void *Steam_Client::GetISteamBilling_old( HSteamUser hSteamUser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -49,7 +50,8 @@ ISteamAppDisableUpdate *Steam_Client::GetISteamAppDisableUpdate( HSteamUser hSte
         return reinterpret_cast<ISteamAppDisableUpdate *>(static_cast<ISteamAppDisableUpdate *>(steam_app_disable_update));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // retrieves the ISteamTimeline interface associated with the handle
@@ -68,7 +70,8 @@ ISteamTimeline *Steam_Client::GetISteamTimeline( HSteamUser hSteamUser, HSteamPi
         return reinterpret_cast<ISteamTimeline *>(static_cast<ISteamTimeline *>(steam_timeline));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // retrieves the ISteamGameStats interface associated with the handle
@@ -89,7 +92,8 @@ ISteamGameStats *Steam_Client::GetISteamGameStats( HSteamUser hSteamUser, HSteam
         return reinterpret_cast<ISteamGameStats *>(static_cast<ISteamGameStats *>(steam_gamestats_tmp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // retrieves the ISteamUser interface associated with the handle
@@ -162,7 +166,8 @@ ISteamUser *Steam_Client::GetISteamUser( HSteamUser hSteamUser, HSteamPipe hStea
         return reinterpret_cast<ISteamUser *>(static_cast<ISteamUser *>(steam_user_tmp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // retrieves the ISteamGameServer interface associated with the handle
@@ -207,7 +212,8 @@ ISteamGameServer *Steam_Client::GetISteamGameServer( HSteamUser hSteamUser, HSte
         return reinterpret_cast<ISteamGameServer *>(static_cast<ISteamGameServer *>(steam_gameserver));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamFriends interface
@@ -254,7 +260,8 @@ ISteamFriends *Steam_Client::GetISteamFriends( HSteamUser hSteamUser, HSteamPipe
         return reinterpret_cast<ISteamFriends *>(static_cast<ISteamFriends *>(steam_friends));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamUtils interface
@@ -294,7 +301,8 @@ ISteamUtils *Steam_Client::GetISteamUtils( HSteamPipe hSteamPipe, const char *pc
         return reinterpret_cast<ISteamUtils *>(static_cast<ISteamUtils *>(steam_utils_temp));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamMatchmaking interface
@@ -323,7 +331,8 @@ ISteamMatchmaking *Steam_Client::GetISteamMatchmaking( HSteamUser hSteamUser, HS
         return reinterpret_cast<ISteamMatchmaking *>(static_cast<ISteamMatchmaking *>(steam_matchmaking));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamMatchmakingServers interface
@@ -338,7 +347,8 @@ ISteamMatchmakingServers *Steam_Client::GetISteamMatchmakingServers( HSteamUser
         return reinterpret_cast<ISteamMatchmakingServers *>(static_cast<ISteamMatchmakingServers *>(steam_matchmaking_servers));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the a generic interface
@@ -539,7 +549,8 @@ void *Steam_Client::GetISteamGenericInterface( HSteamUser hSteamUser, HSteamPipe
     }
     
     PRINT_DEBUG("No interface: %s", pchVersion);
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamUserStats interface
@@ -576,7 +587,8 @@ ISteamUserStats *Steam_Client::GetISteamUserStats( HSteamUser hSteamUser, HSteam
         return reinterpret_cast<ISteamUserStats *>(static_cast<ISteamUserStats *>(steam_user_stats));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns the ISteamGameServerStats interface
@@ -589,7 +601,8 @@ ISteamGameServerStats *Steam_Client::GetISteamGameServerStats( HSteamUser hSteam
         return reinterpret_cast<ISteamGameServerStats *>(static_cast<ISteamGameServerStats *>(steam_gameserverstats));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns apps interface
@@ -625,7 +638,8 @@ ISteamApps *Steam_Client::GetISteamApps( HSteamUser hSteamUser, HSteamPipe hStea
         return reinterpret_cast<ISteamApps *>(static_cast<ISteamApps *>(steam_apps_temp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // networking
@@ -656,7 +670,8 @@ ISteamNetworking *Steam_Client::GetISteamNetworking( HSteamUser hSteamUser, HSte
         return reinterpret_cast<ISteamNetworking *>(static_cast<ISteamNetworking *>(steam_networking_temp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // remote storage
@@ -699,7 +714,8 @@ ISteamRemoteStorage *Steam_Client::GetISteamRemoteStorage( HSteamUser hSteamuser
         return reinterpret_cast<ISteamRemoteStorage *>(static_cast<ISteamRemoteStorage *>(steam_remote_storage));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // user screenshots
@@ -716,7 +732,8 @@ ISteamScreenshots *Steam_Client::GetISteamScreenshots( HSteamUser hSteamuser, HS
         return reinterpret_cast<ISteamScreenshots *>(static_cast<ISteamScreenshots *>(steam_screenshots));
     }
     
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 
@@ -741,7 +758,8 @@ ISteamHTTP *Steam_Client::GetISteamHTTP( HSteamUser hSteamuser, HSteamPipe hStea
         return reinterpret_cast<ISteamHTTP *>(static_cast<ISteamHTTP *>(steam_http_temp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Deprecated - the ISteamUnifiedMessages interface is no longer intended for public consumption.
@@ -754,7 +772,8 @@ void *Steam_Client::DEPRECATED_GetISteamUnifiedMessages( HSteamUser hSteamuser,
         return reinterpret_cast<void *>(static_cast<ISteamUnifiedMessages *>(steam_unified_messages));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 ISteamUnifiedMessages *Steam_Client::GetISteamUnifiedMessages( HSteamUser hSteamuser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -766,7 +785,8 @@ ISteamUnifiedMessages *Steam_Client::GetISteamUnifiedMessages( HSteamUser hSteam
         return reinterpret_cast<ISteamUnifiedMessages *>(static_cast<ISteamUnifiedMessages *>(steam_unified_messages));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Exposes the ISteamController interface
@@ -795,7 +815,8 @@ ISteamController *Steam_Client::GetISteamController( HSteamUser hSteamUser, HSte
         return reinterpret_cast<ISteamController *>(static_cast<ISteamController *>(steam_controller));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Exposes the ISteamUGC interface
@@ -858,7 +879,8 @@ ISteamUGC *Steam_Client::GetISteamUGC( HSteamUser hSteamUser, HSteamPipe hSteamP
         return reinterpret_cast<ISteamUGC *>(static_cast<ISteamUGC *>(steam_ugc_temp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // returns app list interface, only available on specially registered apps
@@ -871,7 +893,8 @@ ISteamAppList *Steam_Client::GetISteamAppList( HSteamUser hSteamUser, HSteamPipe
         return reinterpret_cast<ISteamAppList *>(static_cast<ISteamAppList *>(steam_applist));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Music Player
@@ -884,7 +907,8 @@ ISteamMusic *Steam_Client::GetISteamMusic( HSteamUser hSteamuser, HSteamPipe hSt
         return reinterpret_cast<ISteamMusic *>(static_cast<ISteamMusic *>(steam_music));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Music Player Remote
@@ -897,7 +921,8 @@ ISteamMusicRemote *Steam_Client::GetISteamMusicRemote(HSteamUser hSteamuser, HSt
         return reinterpret_cast<ISteamMusicRemote *>(static_cast<ISteamMusicRemote *>(steam_musicremote));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // html page display
@@ -918,7 +943,8 @@ ISteamHTMLSurface *Steam_Client::GetISteamHTMLSurface(HSteamUser hSteamuser, HSt
         return reinterpret_cast<ISteamHTMLSurface *>(static_cast<ISteamHTMLSurface *>(steam_HTMLsurface));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // inventory
@@ -942,7 +968,8 @@ ISteamInventory *Steam_Client::GetISteamInventory( HSteamUser hSteamuser, HSteam
         return reinterpret_cast<ISteamInventory *>(static_cast<ISteamInventory *>(steam_inventory_temp));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Video
@@ -961,7 +988,8 @@ ISteamVideo *Steam_Client::GetISteamVideo( HSteamUser hSteamuser, HSteamPipe hSt
         return reinterpret_cast<ISteamVideo *>(static_cast<ISteamVideo *>(steam_video));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Parental controls
@@ -974,7 +1002,8 @@ ISteamParentalSettings *Steam_Client::GetISteamParentalSettings( HSteamUser hSte
         return reinterpret_cast<ISteamParentalSettings *>(static_cast<ISteamParentalSettings *>(steam_parental));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 ISteamMasterServerUpdater *Steam_Client::GetISteamMasterServerUpdater( HSteamUser hSteamUser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -986,7 +1015,8 @@ ISteamMasterServerUpdater *Steam_Client::GetISteamMasterServerUpdater( HSteamUse
         return reinterpret_cast<ISteamMasterServerUpdater *>(static_cast<ISteamMasterServerUpdater *>(steam_masterserver_updater));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 ISteamContentServer *Steam_Client::GetISteamContentServer( HSteamUser hSteamUser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -1006,7 +1036,8 @@ ISteamGameSearch *Steam_Client::GetISteamGameSearch( HSteamUser hSteamuser, HSte
         return reinterpret_cast<ISteamGameSearch *>(static_cast<ISteamGameSearch *>(steam_game_search));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Exposes the Steam Input interface for controller support
@@ -1025,7 +1056,8 @@ ISteamInput *Steam_Client::GetISteamInput( HSteamUser hSteamUser, HSteamPipe hSt
         return reinterpret_cast<ISteamInput *>(static_cast<ISteamInput *>(steam_controller));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 // Steam Parties interface
@@ -1038,7 +1070,8 @@ ISteamParties *Steam_Client::GetISteamParties( HSteamUser hSteamUser, HSteamPipe
         return reinterpret_cast<ISteamParties *>(static_cast<ISteamParties *>(steam_parties));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 ISteamRemotePlay *Steam_Client::GetISteamRemotePlay( HSteamUser hSteamUser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -1056,7 +1089,8 @@ ISteamRemotePlay *Steam_Client::GetISteamRemotePlay( HSteamUser hSteamUser, HSte
         return reinterpret_cast<ISteamRemotePlay *>(static_cast<ISteamRemotePlay *>(steam_remoteplay));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 ISteamAppTicket *Steam_Client::GetAppTicket( HSteamUser hSteamUser, HSteamPipe hSteamPipe, const char *pchVersion )
@@ -1068,7 +1102,8 @@ ISteamAppTicket *Steam_Client::GetAppTicket( HSteamUser hSteamUser, HSteamPipe h
         return reinterpret_cast<ISteamAppTicket *>(static_cast<ISteamAppTicket *>(steam_app_ticket));
     }
 
-    report_missing_impl_and_exit(pchVersion, EMU_FUNC_NAME);
+    report_missing_impl(pchVersion, EMU_FUNC_NAME);
+    return nullptr; // unknown interface version: emulate real steamclient (null), never exit
 }
 
 void Steam_Client::report_missing_impl(std::string_view itf, std::string_view caller)
@@ -1108,11 +1143,13 @@ void Steam_Client::report_missing_impl(std::string_view itf, std::string_view ca
     }
     catch(...) { }
 
-#if defined(__WINDOWS__)
-    MessageBoxA(nullptr, ss.str().c_str(), "Missing interface", MB_OK);
-#endif
+    // NOTE: no MessageBox here. The blocking "Missing interface" modal could
+    // fatally stall/kill games under Proton/Wine. report_missing_impl is now a
+    // pure (non-blocking, non-exiting) logger; callers decide how to recover.
 }
 
+// Legacy: log + hard-exit. No longer used by the interface getters (they now
+// return null like real steamclient on an unknown version) — kept for compat.
 void Steam_Client::report_missing_impl_and_exit(std::string_view itf, std::string_view caller)
 {
     report_missing_impl(itf, caller);
diff --git a/premake5-deps.lua b/premake5-deps.lua
index 2c9a04631..e6a9df7be 100644
--- a/premake5-deps.lua
+++ b/premake5-deps.lua
@@ -550,11 +550,26 @@ if _OPTIONS["build-zlib"] or _OPTIONS["all-build"] then
     local zlib_common_defs = {
         "ZLIB_BUILD_EXAMPLES=OFF",
     }
+    -- The current zlib installs its static lib as 'zs.lib', but downstream deps
+    -- (protobuf, curl) are pointed at ZLIB_LIBRARY=.../zlibstatic.lib by wild_zlib.
+    -- Mirror zs.lib -> zlibstatic.lib after each build so those hardcoded paths
+    -- resolve on a clean build (a stale zlibstatic.lib used to hide this on warm runners).
+    local function mirror_zlib_static(arch_iden)
+        local libdir = path.join(deps_dir, 'zlib', 'install' .. arch_iden, 'lib')
+        local zs = path.join(libdir, 'zs.lib')
+        local zstatic = path.join(libdir, 'zlibstatic.lib')
+        if os.isfile(zs) then
+            print('mirroring ' .. zs .. ' -> ' .. zstatic)
+            os.copyfile(zs, zstatic)
+        end
+    end
     if _OPTIONS["32-build"] then
         cmake_build('zlib', true, zlib_common_defs)
+        mirror_zlib_static('32')
     end
     if _OPTIONS["64-build"] then
         cmake_build('zlib', false, zlib_common_defs)
+        mirror_zlib_static('64')
     end
 end
 
diff --git a/steam_old_lib/dllmain.cpp b/steam_old_lib/dllmain.cpp
index 73fd974be..545fab2c0 100644
--- a/steam_old_lib/dllmain.cpp
+++ b/steam_old_lib/dllmain.cpp
@@ -18,12 +18,13 @@
 
 #include <Softpub.h> // WinVerifyTrust
 
-#ifndef EMU_RELEASE_BUILD
 #include "dbg_log/dbg_log.hpp"
-#endif
 
-
-#ifndef EMU_RELEASE_BUILD
+// Define the global dbg_logger unconditionally: PRINT_DEBUG (common_includes.h)
+// references it in release builds too now (the GSE_FORCE_LOG refactor gates logging
+// at runtime via dbg_log::is_active(), not at compile time). base.cpp defines it the
+// same way; leaving this under EMU_RELEASE_BUILD made lib_steam_old fail to link in
+// release (LNK2019 unresolved dbg_logger).
 dbg_log dbg_logger(
     []{
         static wchar_t dll_path[8192]{};
@@ -33,7 +34,6 @@ dbg_log dbg_logger(
             + "STEAM_OLD_LOG_" + std::to_string(common_helpers::rand_number(UINT32_MAX)) + ".log";
     }()
 );
-#endif
 
 
 static bool dll_loaded = false;