Only in the last week, there have been at least 5 server crashes / sudden restarts, that I know of. It is mostly happening on 313 and 215, others possibly too. There seems to be no common denominator: it happens during boss fights, just before transitioning, or for no other apparent reason (no runs on the server whatsoever). Last one occured on Sun 13/03/16 around 16:40 CET, on 313, to give an example (Tia run was in progress).
Yeah, looks like u can cs anythin non crit imm. - Big Crit
With the exception of crashing upon killing Quimath (confirmed to be due to loot table changes at the time), I have not had *any* crashes in the last few weeks.
Though I can confirm that I've seen it happen to other players a LOT. Which makes me suspect there is some common denominator (class ability, or relation to party size?); we just need to figure out what it is.