I had some issues with one user who was not able to open a Microsoft Access database on a shared drive. The user would try to open the database, and it would only allow the user to use it as read only, which was not very useful. Every other user was able to use the database with out any trouble. There were no issues with permissions on any other databases on the shared drive or with any linked tables.
We were able to fix the issue by going into the permission for the database (Right Click -> Properties -> Security) and adding the user directly as an administrator to the database. I have no idea why the user suddenly had issues accessing the database, as they had been using it on a daily basis for about a month with no issues. Hopefully, this tip might save you some headache.