Is this about the PC version ?
What are your PC specs?
With mods, or without mods? Mods can be the source for all sorts of issues
It is always helpful to provide these infos.
Also, this is the official support website from CDPR, with infos regarding various potential problems:
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
The topic for crashes is this one, for example:
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
(there‘s a contact link there too)
Closing all non essential background applications is also recommendable and disabling overlay features of background applications.