During combat my Signs/right click powers will stop working for no reason. My endurance bar will be at full but no amount of right clicking will cast them. There doesn't seem to be a pattern to this.

Also when starting combat Geralt is very slow to pull out his sword. This often means enemies will get 2-3 hits in first before you can start combat, if you're in a group then you get stun-locked and can lose 1/4 of your health before you even draw your sword.

Have you tried reselecting your signs with the number keys? I've noticed that when you go into a safe area between combat that your signs are also unselected.

I have them selected and swap around but right clicking does nothing.

Is this built in to stop using signs against certain monsters which are immune to knockdown?

Either way I finished the game, a few little bugs and the sword drawing delay should be fixed but all in all its an amazing game. Looking forward to the second one.