[Neoptolemus]

This is really weird.

To rule out the possibility that the bot is looking in the wrong direction, I have am now forcing the bot look directly upwards all the time (v.origin + Vector(0,0,100)) and the bot is still rooted to the floor when touching a ladder.

I had assumed that pEdict->v.v_angles were the view angles, and pEdict->v.angles were the movement angles. However, when I implement your fix for the code, Immortal, the bot looks the wrong way (i.e. he looks at his feet, not upwards). This is both in first and third person. To me this suggests his movement and view angles are both being modified even though the code doesn't do this.

I have tried every possible combination of inputs into pfnRunPlayerMove, including both v.angles and v.v_angle in the second parameter, using the inversion in LookAt and not using it, and setting the upmove parameter to maxspeed.

I really don't get this at all :-(

EDIT: This also happens on official maps, and even if the bot accidentally touches a ladder while moving elsewhere. In other words, they're trying to move AWAY from the ladder, but by accidentally touching the ladder they become completely frozen and unable to move until they die or I restart the round. Seriously, what the hell?