Put "-dontForceMinReqs" in properties -> Launch options

During prologue after you defend Kaer Morhen from sorcerers, Leo's funeral is being held. After the funeral cut scene Vizima's map starts to load but it never loads completely.

Solution:
Disable auto-save and restart the game. Start from a save before cut scene when the scene starts press esc or space to cancel the clip. This time Vizima should load just fine.