error entering font mode no data

I have the following OSD: https://www.banggood.com/3DR-Micro-OSD-For-APM2_5-2_6-2_8-Pixhawk-PX4-Flight-Controller-Mini-Quadcopter-FPV-p-980860.html?rmmds=myorder&cur_warehouse=CN

minimosd-extra can be flashed successfully, but when I try to write the charset, the error: "error entering font mode no data", is shown. I powered the video side with 12V, but no success. Any hints?

Found Character_Updater firmware - issue closed. It would be user-friendly, if the desktop software would give this information as a hint. The message "error entering font mode no data" is not helpful.