Basically upon entering Solitude for the first time, after executing the prisoner, the guards run after me. I can't yield and stop the fighting, if I fight back more people come to attack.
I have no bounty and have committed no crimes. If I reload to a save 5 minutes earlier and try to enter again, the same thing happens.

Ok, entered through a different entrance, and it worked fine. If you run into this bug, give that a go.