We have been sharing a Filemaker Pro 9 database across our office network successfully for the last few years. Recently we are receiving the error message:

“Filemaker cannot share files because another user is already sharing files using Filemaker Pro on this computer”

This is appearing on all computers on the network when they try to access the database resulting in only one person at a time being able to access. Machines have been rebooted and Filemaker file sharing is active on all the machines (which are running windows XP). Any help would be appreciated.

This is a license conflict. Each workstation needs its own license code. Did you reinstall FM recently? Do you have a site license? FM9 hasn't been around for "a few years." Did you recently upgrade?

If only it was that simple. Each machine has its own licence and they haven't been upgraded recently. They have been working fine with these installations for months so I'm not sure what has recently changed.

The strange thing is that we receive this message when the first person opens the file so its not a question of Filemaker already being open.

Then, perhaps, it's an activation issue. You'd need to call FMI support.