Laptop arrow is gone?

I wanted to use my laptop & write applications but suddenly the mouse arrow is gone. I've already entered every key combination but nothing helps.

But I suspect that the keyboard has also been turned off, anyway
in any case do not get any further because the mouse is no longer on view and the keyboard does not seem to work either.

In any case, liquid etc. Did not come up with it. Need help quickly as I have to get my applications ready 😕

Have you tried a complete restart?

Yes, several times 😕

Hm. Look here (even if I'm almost sure that you've already read all of this)

https://praxistipps.chip.de/...-tun_35180

Already read & tried everything.