A scanner failed for a reason that PDQ Inventory didn't know how to handle.
The cause will depend on the nature of the error. Check the error message included with the error.
Many times the cause is corruption in the .NET framework on the target computer, requiring a repair or reinstall.
Another possibility is that the target computer was either booting up or shutting down. You will also get this error if you attempt to scan a computer that is configuring Windows' updates or a service pack installation prior to restarting.
In this state (configuring updates) the target can be seen on the network but the OS cannot be accessed or managed.
If repairing or reinstalling .NET on the target computer doesn't work then submit the error to Admin Arsenal support. Our support staff can perform additional research in to the cause and fix for the error.