Since you've already restarted Ninja and repaired the database (hopefully repaired, not reset, ugh I hate resets -- such a waste) then I hope you will take a minute and email ninja support and see what they say.
I'm assuming you've checked the Log and you don't have any historical server errors?
I also assume you are on the latest NT 6.5 build, as several weeks ago there was a mandatory upgrade specifically related to historical servers (they switched them for NT7 and discontinued the 6.5 servers, if I recall correctly).