Failed to load PlayerSettings (internal index #0). Most likely data file is corrupted

My group has recently returned to Fantasy Grounds Unity, but after updating it and executing the software, I get a "Failed to load PlayerSettings (internal index #0).
Most likely data file is corrupted, or built with mismatching editor and platform support versions." error.

I do use Unity (a 2d/3d/AR) editing software though I am not sure if the 'Unity' suffix to Fantasy Grounds is an indicator that this software is used.

Has anyone else encountered this issue or know of a fix?

Thank you.

Disable all extensions, update and try again. Then try with a new campaign
Yes FGU uses the same Unity Game Engine that other Unity programs use, so it is possible their is a conflict, but I haven't heard of such before.
If you do continue to have this issue, please collect the log files (see link in my signature) and post here so we can get more details.

You might have better luck uninstalling and reinstalling Fantasy Grounds, so it resets all the setting files. We upgraded to a newer version of the Unity game engine over the summer, so I'm guessing it's related to Unity engine not handling the old Unity player settings file format. Since this is outside of our code and part of the Unity wrapper, it's not something we have direct control over or can intercept.

Regards,
JPG

Can you tell me what version of Unity you are using?
I presently have 2021.2.3f1 and 2020.3.23(LTS) loaded through the Unity Hub.
Edit:
Fixed the problem. I uninstalled the FGU program and deleted the directory under the appsdata directory then reinstalled. That fixed my problem.
Thank you.