We use vmware as compute resource, and if our vCenter server is down for some reason we can't edit hosts at all in Foreman. We only get the error message:

 Oops, we're sorry but something went wrong Got HTTP 503: Service unavailable

It would make more sense in these instances if just the vm configuration tab was inaccessible. As it is now, we cant edit any puppet parameters even though they are completely independent of any compute resource capabilities.