I reached this part of the game, just after the wild hunt attack Kaer Mohern... and after a few missions, he doesnt climb the edges!!! he just jump against the wall, im lvl 26, i know how to climb, i was doing this mission where you have to help Ciri to stole some horses, and I have to climb the stables, and he doesnt do it!!!!, not there, not anywhere!
The game is updated, and i did something I read that it was, save the save games else where, begin a new game, and then put the old saves again, but it doesnt work :( I cant play anymore! please help!!!

I can't help you, but perhaps check the Witcher 3 subforum?
https://www.gog.com/forum/the_witcher_3_wild_hunt#1442565636

Also you can try enquiring in the official CDPR Witcher 3 forums.Hopefully there will be better chances of someone helping you there with this issue.

forums.cdprojektred.com/forums/174-Tech-Support

Thank you!! Today I enter with the gog Lunch, and I use the repair button, and its fixed!!! :)