We've recently upgraded our pre-production ZCM zone from v10.3.1 to 11.1a. Most parts of the upgrade have gone well.
One issue is that when having upgraded the Zenworks Adaptive Agent on workstations from version to version that ships with Zenworks 11.1a, we're unable to perform inventory scans. Those machines still running agent can still be scanned.
Looking in the properties of a 11.1 agent, the "Inventory" link is missing from the left-hand pane.
When forcing an inventory scan of the workstation from ZCC, the workstation log shows - amongst other things - "Could not find a handler associated with the following type: Inventory.Scannow".
If I manually remove and then reinstall the 11.1 agent, the inventory option is available.

If anyone else has seen something similar and knows of a resolution, I'd love to know about it.
I'll continue to dig into this and will post back results.

Thanks in advance,