500 Error When Trying Setup Compse and Portainer

I'm trying to update my current version of Portainer and I understand I need to setup the compose plugin before I do so. I'm following the steps provided here: 16 Steps to install the new compose plugin and add portainer but once I get to step 5 and hot apply I get a 500 error saying something of the sort that docker is already running. I've tried stopping the service but it restarts on its own by the time the apply config can finish.

Any suggestions? Should I start from scratch and reinstall docker/portainer?

Quote from ryecoaaron

Copy and paste the entire error from the bell in the top right of the omv web interface. What version of OMV?

Here's the screenshot. I tried also copying the entire error but it gets cut off at the end. I'm running version 6.9.16. Should I upgrade?

Sorry about that. misunderstood. I attached the error here. It seems something to do with a public key issue.

Quote from ryecoaaron

I would disable backports using the omv-extras button.

That did it! Thank you! I'll finish the setup and then do an upgrade to the new version.