Great job! Sometimes the files (or cached data for those files) can be corrupted in some way. Often enough, (like you tried originally) wiping the caching folders corrects this, but sometimes the only thing you can do is run the debugger, finding the offending asset, then try to correct it if possible at best or replace it at worst. Data types like structs and enums can end up having this issue in larger projects. This is where I always recommend to every user to have some form of source control (Git, Perforce, etc) and use it frequently. Even when working on a project alone, the benefits of source control are innumerable!