Issues - Windows Platform
There are issues some users might run into on Windows when using Godot and GodotSteam.
No SteamClient023 Error
Some people have experienced this error when running their Windows game on Linux or Steam Deck through Proton; though it only happens with Steamworks SDK 1.63.
The reason is SDK 1.63 is only supported on Proton 10.0-4 or higher, including Experimental.
At the time of writing, you must use 10.0-4 or Experimental to avoid this error. Alternatively, just create a native Linux build and ship that instead.
Failure To Load - Steam Version
If you are using the Steam version of Godot on Windows, you will probably run into a situation where GodotSteam's GDExtension version fails to run. This is usually caused by the version of teh steam_api64.dll shipped with Godot being older than the one GodotSteam uses. This fix, however, is quite easy.
Just copy the steam_api64.dll from the GodotSteam plug-in (res://addons/godotsteam/win64/) and paste it into the Godot folder where ever Steam has installed it. Overwrite this version and now GodotSteam should be able to function again.
At the time of writing, I am looking into adding a script to check for this outdated file and overwrite it auto-magically.