When moving my cursor over a joint, it does not select it, i have to click it first. This is very annyoing. Started today, i use a new installed client version.

It was like: i played a game, everything is normal, next game i cant select the joints.

Except this everything works.

Problem is: The joints dont react when i move my mouse over them

restart the game if you haven't already.

if that doesn't fix it try restarting your computer itself.

if all else fails verify game files and things.

this does not work :/ is it possible that a trojan virus is the source of my problems? I suspect something in that direction.

Would be very strange if a virus caused a problem like this.
Try to reinstall the game or download the steam version if you aren't using that already.

This is a semi-rare issue with seemingly the newest update. Try logging out of your account and then back in. It should fix it. Otherwise just relax a while and it'll reset somehow.

Try resetting your mouse button settings in tb?

Other than that I don't know, can't get on a pc right now to try emulate your issue, perhaps it's similar to the 3D obj not loading that I've had from new updates. Needed to set to a different preset setting and back to fix.

This is an issue that has already been solved by help squad in irc. Seems there was an issue with the newest version, and reosuke's pc.
problem solved by downgrading to 5.11, which seems to work fine