Error in Access when opening a database on a network file share
Microsoft Office updates released around the 15th December caused a problem with some Access databases where the files were stored on a network share.
You are likely to see an error saying “file already in use” or “could not lock file”.
These problems have been fixed by a subsequent Office update but you may need to force you machine to apply these updates in order to fix the problem.
For further information please see this Microsoft article: https://support.microsoft.com/en-us/office/error-in-access-when-opening-a-database-on-a-network-file-share-6cbc1560-62c2-46e7-9980-d079a46f5acc