When I start my Linux Mint, the first display I met is the Login-Display. I am asked for my username and I can type using my wireless keyboard, the username is beeing displayed correctly. But after this I am asked to enter my password, I type and see how with each hit on the keyboard a star symbol appears, but when I am finished and press enter I get everytime an error message.
My username is made out of lowercase alphabetic letters without any special character.
My password is made out of lowercase alphabetic letters and two special characters: ) and (
Once I logged in and use the wireless keyboard to enter the password inside the shell, the password gets accepted.