Upgrade fails because DB is locked

If upgrade fails and in log you have:
Error duringUpgrading Database (Data File: UpgradeData2.sqlce) Error: There is a file sharing violation. A different process might be using the file. [ \\Folder\folder1\Solvency-II\Tabular\Tabular Main Workbook\ProgramData\Tabular.sdf ]

What this is saying is that something is locking the database. To fix:
1. Check if other users from your team are not logged into Tabular.
2. Close all Excel instances and check in Task Manager if there is not an Excel process left behind as this sometimes happens and might be locking the file.
3. Restart your PC

Then run the upgrade again.

In most cases this should work. There are however there are 2 more cases where you can get this error that might need some additional configuration:
1. Some antivirus configurations lock the database and it can’t be updated. To test just disabled the AV for a while and try again. If that indeed was the problem an exclusion in antivirus policies should be made for Tabular.sdf file.
2. If you are using Microsoft Sync center to cache your network drive for work offline, sometimes it might misbehave and block the database. To fix just stop/pause the sync or check in it for conflicts and resolve them. Note that usually restart of the PC will also help.