Delete the prefs and for the rest of the troubleshooting start only with factory defaults.
If Cubase is crashing upon reading a file, the file must be in your system, or the prefs are corrupt - so delete or rename them (again, if nec. 
)
Also rename/delete earlier versions’ Cubase prefs. A fresh Cubase install might be looking for old prefs to sync. (this changed, but I don’t know when)
As far as searching, only 3rd party tools like “EasyFind” actually look everywhere.
PM me if you feel like doing a remote screen share today. I’m bored… (CST)