[UE5.1.1] LogAssetManager: Error: Registered PrimaryAssetId DataTable:DT_XXXX for asset /SomePlugin/DT_XXXX.XXXX does not match object's real id of ! This will not load properly at runtime!

Saving a datatable or string table…

So apparently you can’t manage these classes with the asset manager without setting this checkbox:

Reason being they don’t implement GetPrimaryAssetID as mentioned here:

Can't package project with own DataAssets

Which is funny because you have to be able to reference them there in a 100% c++ project or they simply don’t get loaded.

Side note: Wish this thing was more like a .gitignore where you can load your own whitelist / blacklist of assets to get loaded, cooked, packaged etc… Current system blindly assumes that “unreferenced” assets should not be loaded while in reality unreferenced does not mean unused. The core idea fails.

A discovery? I don’t understand what you wrote.