This used to happen rarely. For the past few months it almost always happens, and I've seen it across tenants. After installing an Enterprise Gateway upgrade, the spinning ants happen after the update finishes, then after a few minutes, I get this:
Then I click "Retry" and within 3 seconds it starts running. Something isn't happening correctly after the install, and I have to wait 2-3 minutes for this error to happen and hit Retry.
I've seen this on stand alone gateways and gateways in a cluster.