We have found so far three issues causing problems with climbing. As of now two of them are being fixed as I write this and hopefully will make it into next patch. The last one is more complex but we'll do our best to nail it down as well.
If you want you can send us your saves through http://en.cdprojektred.com/contact-support and we will check them to see if there are any more potential issues with climbing and fix those ASAP as well.
I want to assure you that all and any bugs related to blocked functionality are being given highest priorities in gameplay and quest teams.
As there is no fix for this bug i have a solution that can help you climb the ledges. First you need to download 'Debug Console Enabler' from
After this open your game and press '~' or 'F2' to open the console and enter "replaceplayer('Ciri')" without the quotes. This will change Geralt to Ciri. Now climb the ledges with Ciri and then change the character back to Geralt using the same command "replaceplayer('Geralt').