Comment 3 for bug 1627127

Ok, it definitely seems to be caused by the invalid resource revision. The resource revision was caused by a conflict between cs:trusty/apache-zeppelin and cs:apache-zeppelin (the latter being multi-series and including resource support).

This seems to be caused in the charm store by reverting from a resource-enabled revision of a charm to a non-resource-enabled revision on a given channel and then deploying the resource-enabled revision from another channel (or by explicit revision number). It's more of an issue with the charm store, but it may be worth handling the case in Juju to avoid this on the off chance it comes up.