Manager Error 'Bad File name or Number'

Open Administrator and go to File/Configuration.

Check the Paths and Templates Tabs - you probably have an invalid path or filename in one of those fields. If you are using files shared on the network, you may not have permission to access the files or folders.

We had this problem at a customer and, according to MS support, this indicates a network or file sharing error. Like Glenn said, check network share permissions, but also check network settings, network ports, cables, etc. Our customer had made a change to their network switch/router which caused them to drop their connection.