So I´ve had some problems with the lighting of the keyboard, so I´ve googled and found the hard reset. After doing it, the lights worked again as they should and I could set like I wanted, but I couldn’t write anymore. I tried deleting the driver and installing it again, I tried the hard reset again, I tried the Key combination to get out of demo mode. I even tried a tool I found in the forums, which cleans all drivers so I could reinstall them, still no fix until now. Of course I tried reinstalling Synapse too. Now I don’t find any other solutions in the forum or anywhere else for my problem.
Hope you guys can help me with that.

