Revit is unable to reclaim a license that has been taken away by the TIMEOUTALL variable in the Options file.
You run Revit 2010 and get a network license. Leave your desk and come back after the TIMEOUTALL period reclaims your Revit license back to the Flex License Manager. At this point you cannot just move the mouse and get another license.
This is a known issue that is being worked on and Autodesk recommends that you remove the TIMEOUTALL variable from the Options file.
As a workaround:
Use the TIMEOUT variable to time out all your features except Revit. This can be a large undertaking depending on how many features you need to time out. If you have a license file that contains the PACKAGE feature there will be 4 lines of code needed just for that license alone.
If you need any help on this or any other issue call the Avatech National Support Center at 800-808-7645. Remember our contract holders come first and first time callers after that. If you’d like to purchase a support contract we can help with that too.