When starting Quickmap, you may get this error:

Quickmap: Unexpected Error Encounted

Database provider <unknown> not currently supported.

This happens because the data is corrupt. To fix this, reinstall the data.

Data typically gets corrupted if the files in the data directory are manipulated with a program other than Quickmap (such as antivirus, or a user manually moving the files around), or if you are using file synchronization on the data directory, such as with Dropbox or OneDrive.