To compact the database, follow the steps below:
Make sure all users have exited that particular database.
Click File, Maintenance, Database, Maintenance.
Click Yes to do the backup and save it to your backup location.
Once the backup is complete, click Ok; this will bring up the Database Maintenance Wizard.
Click Next and Next as you will be selecting the default database as this is the one you are currently in and needs to compact.
Tick the Compact Database and then click Next.
Once the database has finished compacting, click Finish and then log in and you should be able to get into that employee’s file.
Note: In most cases, running the process of Compacting the database will fix Diagnostic Errors.