I have a report that I added to the Design Master of a replica. The report previews based on criteria entered into a form/query. If I preview the report from report design and type in my criteria, it works fine, but when I try to preview it form a command button on the form after selecting the criteria, I get the following error "The database engine could not lock table 'customers' because it is already in use by another person or process'. If I then look in the MyDocuments folder, I can see my Access Application as normal and also one that lists the type as Access.LockFile.9 . As ususal, any suggestions are greatly appreciated.