FogBugz On Demand is being upgraded to version 8.12.918 on 4/23/15.
This will be one of our usual FogBugz upgrades: it will be rolled out to larger and larger groups through the day, starting at 0800 EDT and completing by 1700 EDT. There won't be any impact on availability during that time.
However, we've also got a small database change with this one. At your local midnight (based on the time zone set on your account), you'll experience a short service interruption of up to five minutes.