I have a site that I ran into this problem. Document scanner was set up to scan to a shared 'Scanned' folder. I would always get an error. Called Xerox support and we went though a bunch of processes that didn't get us anywhere. This is a WIndows 7 Pro machine.
Today, I decided to disable the antivirus and sure enough that worked. Turned it back on and the scan to folder stopped with an error. We run MSE on that system. I went though the settings and didn't find anything that I would think that would cause it to stop the scanning to folder.
Does anyone know what to disable in MSE to allow the Xerox to save to that folder?