You can try verify/repair as mentioned in this support article:
support.cdprojektred.com
You can also contact support by clicking on „contact us“
That being said, when the game is stuck often I would just recommend going back to an older save game.
However, if mods are installed that could also be the issue.
I am unable to complete/progress in a quest — The Witcher 3: Wild Hunt | Technical Support — CD PROJEKT RED
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com
You can also contact support by clicking on „contact us“
That being said, when the game is stuck often I would just recommend going back to an older save game.
However, if mods are installed that could also be the issue.