Resetting my Sim, teleporting them works though that does not fix the profession as a whole. I can't progress through the profession if I keep resetting the Sim and I want to do it. I contacted support and the end solution was re-installing the game to see if this happens again or not.
hope you have't uninstalled your games yet one thing to try before you do all that is save your household to the libary start a new game move the household into your new game it means a new career start for your firefighter but will level up as he/she will have all the skills when you save them to the libary
