Looking at the Ratings table from career.pbb in SQLiteStudio, the PlayerID is showing Integer for the Data Type but the actual data is a String (e.g. smitsc01).
I don't know if that is an error in SQLiteStudio (it opened the file as a SQLite 3 file) or the Ratings table in career.pbb is messed up. I was trying to get my team's player ratings changes over several seasons. I was able to work around it but I thought that I would mention it anyway.
Running version 9.12.