We apologize for the instability of composr.app and appreciate your patience. We are working on the statistics addon and trying to find an optimal way to store and render data. Unfortunately, we have yet to find a solution that can handle the traffic (and therefore, tens of millions of statistical records) of composr.app. We're working hard on one.
I personally could not reproduce on Composr 10RC16 :( . However I'm using the very expert page scheme, not the simple scheme as it appears in the error. Chris might find the issue.
#2780 - Attempting to edit catalogue creates major error dump