I won't claim with a 100% certainty that this is the problem, but I think it is mostly in the mod file themselves. From my own experience, in EA when I made my mod that adds an extra skin color I could change the "DisplayName", which had a "FixedString", to give it a name with plain text. Now in full release it is a "TranslatedString" and now requires a handle of letters and numbers. Example:
<attribute id="DisplayName" type="TranslatedString" handle="h57a7b9feg02cbg4661g9554g75b75678aade" version="1"/>
Doing it with plain text causes "Not Found", and changing it to a "FixedString" caused the game to crash with the mod. I decided to leave it blank with my mod for now, as I felt "Not Found" would be more confusing. Not sure what needs to be done to change these to say the right thing, perhaps it is using the handle to get the name from some other file. Hopefully someone will figure it out.