Tips from Upgrading "Legend of the Stones"

I'll be honest. It's been too many months since I've worked on my own RPG project, Legend of the Stones. To be fair, I've spent that time working on Game Modules 4, so perhaps it's an OK tradeoff!
I've installed the new Game Modules 4 into the project, and as expected, many things broke. I'll be fixing them, and the sections below may be similar to issues you face if you upgrade from a previous Game Modules version to version 4.
Come to the Discord to chat more!

Two "GameStatList" classes

I don't know how this happened, but there are two GameStatList classes. I'll remove the old one. The old one has a comment at the top with "GAME STATS LIST".
Also, if "GameStatsList" (with a plurel Stats) exists, remove that.

The type of namespace "Inventory" does not exist

True. It is now "InfinityPBR.Modules.Inventory".
If you are using the Inventory system, any references to InfinityPBR.Inventory should add "Modules." in the middle.

[Class] does not implement interface member [XYZ]

Some interfaces now have new required methods. If you're using an IDE, it should be easy enough to add those, and then decide which ones you'll make use of.

Error: StatsRepository.GetStatByUid(uid);

Repositories have a new "Get" method.
StatsRepository.GetStatByUid(uid); should now be StatsRepository.statsRepository.GetByUid(uid);
Note the change of "GeStatByUid" to just "GetByUid".

.uid is now .Uid()

gameStat.uid would now be gameStat.Uid()