Had weird behavior in our non-admin server:
· SAM worker was dead with these errors:
Process samworker was not running, restarting it
An unhandled exception occurred: Could not connect to net.tcp://127.0.0.1:13279/WorkerConfigStatusService. The connection
WorkerLibrary.dll:Listen - SocketServer ESP_Socket_Server error listening on port 13270 Main Exception: Only one usage of each socket address (protocol/network address/port) is normally permitted [System.Net.Sockets.SocketException]
· Many crawled items returned with warnnings about Fast backend access issues:
The FAST Search backend reported warnings when processing the item. ( Document conversion failed: Access is denied. )
· Many of the files in the non-admin server seemed to be locked 
· Many of the items seemed to be in use, with ~ sign at its beginning. 
All these issues were cumulated along the time, and didn’t seem to be connected.“BINGoogled” it, asked many experts about it, but nothing helpful was found….
Here is how all these issues were solved:After investigating, found that the common thing between all the above was that Fast engine tried to use one of its files, but it couldn’t do so due to permissions / ‘file in use’ issues. So:
· Stopped Fast search main service.
· Fast folder Permissions:
o Added to the %fastsearch% folder permissions, the FASTSearchAdministrators group members one by one, with full control.
o Made all child objects to inherit permissions
· Removed used files:
o Went over all the %fastsearch% folder and deleted all the tilda ‘~’ beginning items.
· Started the Fast for SharePoint main service
“Et Viola” – all the above issues (and I’m sure that many more we weren’t aware of) were solved :)
Elad.