M-Files cannot connect to the vault database

Please assist.

Backgroud: The system was in a "Database optimization" when it was interrupted (power went off) since then it cannot be accessed giving out the following message:
"M-Files server cannot connect to the vault database.
Unspecified error. (I/O error for file 'C:\Program Files\M-Files\Server Vaults\AITLINK\MetaData.fdb'
Error while trying to open file
The process cannot access the file because it is being used by another process (ERROR: 335544344, SQLSTATE: 08001)"

Other Vaults are working fine