We've recently upgraded from 4.0.6.3 to 4.1.6 and we've upgraded all of our clusters except one to 4.1 without issue. The one we are having trouble with is the big important one (of course).

The error we get in the interface is:

Error while executing action:

Cannot change cluster version since following VMs are previewing snapshots:

mail-archive1

The log error is a little verbose seeming, so it's attached. I'm not really sure what it means or how to fix it....

Logan