Error 401

MICROSOFT JET DATABASE ENGINE CANNOT OPEN FILE ALREADY OPEN EXCLUSIVELY BY ANOTHER USER OR YOU NEED PERMISSION TO VIEW ITS DATA CAN’T SHOW MODAL NON-MODAL FORM WHEN MODAL FORM IS DISPLAYED

Resolution:

Can't show modal non-modal form when modal form is displayed
The Error that follows this message will give you more specific information regarding the cause.

MICROSOFT JET DATABASE ENGINE CANNOT OPEN FILE ALREADY OPEN EXCLUSIVELY BY ANOTHER USER OR YOU NEED PERMISSION TO VIEW ITS DATA

NETWORK ERROR - reconfigure terminals for read & write access. This is something that must be done by the network admin.