Error code "AUS 7B" for rheavendors XS

Hello dear.
I have a problem with the machine, which type can you possibly take from the label.

As already described in the headline, the error "OFF 7B" occurs again and again.

First it was like this, you turn on the machine after some time, it prepares. One can let out a coffee. If you then want to let out another one, it clicks 2 times, and shows the error.
After switching off and on again, the error is still there. Only if you let it stand overnight, you could let out a coffee again, as described above.
If you went into the maintenance menu, the machine kicked you out again after 5 seconds.

What could this be due to? Does anyone here have any ideas?

Here the label