Problem continuous crash of all players and start of the game from the previous backup - (10 Player Realm Server Xbox)

I have an xbox realm with 7 players in it. Since this afternoon the server suffer continuous crahes (one every 5-10 minutes) and the server is reset to the last backup. We didn't build big redstone systems or farm, neither lots of entities or anything else that could normally cause crashes.
We can't play on the realm like this doing the same thing over and over again.
I'd like to know what is the problem and if I can do something to solve this problem.