Path/file error and catastrophic failure after inactivitiy

Added some functionality to a project I am working on and now I'm getting the above error if I leave the project open over night.

I added a userform that allows the user to change the default save directory. Anyone see the problem?

userform code:

Please Login or Register  to view this content.

"folder picker"

Please Login or Register  to view this content.

folder validation

Please Login or Register  to view this content.

Thanks in advance!