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.
Go into the upgrader (/upgrader.php) and clear caches, and also run an integrity check. I think it is a corruption in your caches, but a possible cause was a file not reuploading correctly, which the integrity checker would detect.
#1614 - cron_bridge.php cron job spitting out a syntax error