This one always catches me by surprise, and it shouldn't... when we do a major version upgrade (say, 6 to 7 or 7 to 8), it invalidates our license. We always forget to request that the license be released before we do the upgrade, and remember halfway through the upgrade. This drives me nuts! Some alternative solutions:
* Give the system a 3 - 5 day, temporary license after upgrading.
* Allow us to invalidate licenses on our own through the licensing system.
* Allow us to edit a license's version number through the licensing system.
Any of these would be fine, and would stop me from having to call support in the middle of a weekend or in the middle of the night just to get a license released.