I'm trying to upgrade a VM from M58 to M66 so I can use PyTorch 1.8. The upgrade button on "edit VM details" results in "this operation cannot be completed." Any idea why that might be the case and what to do when it happens?
In general terms, upgrading a Marketplace Solution is not the best approach, instead it's better to keep the solution disposable and redeploy a new version when you want, then move all your information and configurations to that new version.
This is because Marketplace solutions depend on the partners not on GCP, furthermore, GCP doesn't even have an official documentation about upgrading a Marketplace Solution (it does have this to MANAGE deployments but it doesn't talk much about upgrades).
So, you made the right choice when you decided to just deploy the new version.