When opening Microsoft Project (MSP), the Clarity Integration tab / toolbar is missing.
Checking MSP's Add-Ins list, it appears as Inactive (or may also be disabled), and its Load Behavior is 'Unloaded' under COM Add-Ins section:
Manually enabling it makes the toolbar appear, but after closing and starting MSP, the toolbar is missing again.
A likely cause is that MSP crashed and the add-in has been unloaded by Microsoft Project as a precaution measure so that the program can be started normally.
Release: All Supported Releases
Update the LoadBehavior entry in the registry for the CAClarityAddin after taking a backup of the registry:
Important: This resolution involves editing the Windows registry. Make sure that you are familiar with editing the Windows Registry and back up any key or value that you modify so that you can undo the changes and roll back if necessary.
'Unloaded' is '0x0000000 (0)') which causes the issue with the addin being inactive
5. Once the above change is complete, reopen MSP and validate the addin now appears.