This currently points at Fsdata (through Loopia). It should be migrated to Bahnhof. Piwik has changed name to Matomo, so it makes sense to change the subdomain accordingly, maybe keeping and redirecting the old one.
My guess is that the old database was corrupted after a failed update (likely without a backup). I think we can live without the old stats since there is a multi-year gap in it anyway. That does however remind me that we should make sure there is a backup routine for that server (which I guess we have by default).