Error message ‘Sentinel Key Not Found’

For ProMass for Xcalibur 3.0 and 4.0 users: Check to make sure your ProMass USB license key is plugged into the computer where ProMass is installed and running. ProMass for Xcalibur versions 3.0 and 4.0 do not support data processing over Windows Remote Desktop.  If you require remote processing capability consider using an alternative mechanism such as VNC or TeamViewer, for example. Alternatively, upgrade your copy of ProMass to version 5.0, which does allow Windows remote desktop processing with one concurrent user.