I upgraded my Octopus Server to version 2019.7.1. After I did the upgrade I tried to upgrade the tentacles in my environment.
About 1/2 of them failed at this at this step:
Running Tentacle version 4.0.1
Waiting for the upgrade to complete
If I look at the log file on the server I see this:
CommandLine: C:\Program Files\Octopus Deploy\Tentacle\Tentacle.exe extract --package Tentacle.nupkg --destination D:\Octopus\Crosspoint-QA\Upgrade\20190711162100-MSEEW --console
INFO 6 files extracted
From what it looks like, it extract the files and does nothing else. I even tried rebooting one of the servers to see if that helped and it did not.
If I manually run the Octopus installer on the server it will update the tentacle