End of Day Unable to Process

We have been consistently getting this error:

Unable to process "end of day". The ShipRush service is not running. The ShipRush service is on the PC "\\senix-sql-01\...". Please reboot that PC and try the end of day again.

Several people are logged into our server at any given time & it is not always convenient to simply "reboot" the main file server.

Can someone explain why this might be happening? Senix has the main ShipRush database on our file server & (2) workstation installations.