Error when attempting to export as json

[Nerdsie]

python3 export_tsm_auctions.py -r /mnt/f/Program\ Files/Blizzard\ Games/World\ of\ Warcraft_old/retail/Interface/AddOns/TradeSkillMaster_AppHelper/AppData.lua -o prices -f json

processing Stormreaver
Traceback (most recent call last):
File "export_tsm_auctions.py", line 192, in
main()
File "export_tsm_auctions.py", line 168, in main
export_dataframe(out, df, args.format)
File "export_tsm_auctions.py", line 81, in export_dataframe
df.to_json(fn, index=False)
File "/home/nerdsie/.local/lib/python3.6/site-packages/pandas/core/generic.py", line 2305, in to_json
indent=indent,
File "/home/nerdsie/.local/lib/python3.6/site-packages/pandas/io/json/_json.py", line 51, in to_json
"'index=False' is only valid when 'orient' is 'split' or 'table'"
ValueError: 'index=False' is only valid when 'orient' is 'split' or 'table'