Often Windows has problems that are just difficult to diagnose and resolve and for resent Windows versions there are fewer public knowledge base articles to help.

In this post we had an issue where offline files started to cause sync to fail. As it turned out the client computer (Windows 10) was trying to sync files of a User than no longer existed on the domain.

Rather than consume our time on trying to diagnose and do the work that Microsoft should be doing we decided on the simple process of formatting the CSC Database.

Create a new entry using regedit

1. Start RegEdit.exe with elevated permissions
2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\CSC\Parameters\
3. Create new REG_DWORD key with name FormatDatabase with value of 1

Reboot the client machine

Sync issues cause by a corrupt database should now be resolved.