Update: It’s able to package and cook when the FMODStudio folder in Plugins is checked out in Source Control.
Without it, FMOD doesn’t seem to have access to the .lib file.
So, if those files (I did the whole folder just to make sure) aren’t checked out, it won’t run.
I’m curious to know why only FMOD fails to build when not checked out, but at least for now it works.
Another interesting error:
In the packaged file directory, the /Content/FMOD folder doesn’t exist. You can run the game but there will be no sound. I had to manually copy the /Content/FMOD folder to the exported game, and then the sound worked. This doesn’t seem to happen automatically.