Ravenjay: I haven't installed any mods and sadly totally reinstalling the game did not make any difference. I'm at the end of my tether now with all of this! My daughter says I can go round to hers and play Witcher on their PS4! Maybe that's what I'll have to do
Bummer to hear. ;/ All I can suggest is to persevere with GOG or CDPR support and supply as much details as possible, copies of save games, any screenshots etc. that might help. They've been really fantastic at fixing bugs in general since the game's release.
Just as a comparison, I played Skyrim all the way through from December 2014 until about March 2015 and according to Steam I put in 645 hours. Of that probably 575-600 was actual game play with the rest idle time eating with the game paused etc. Skyrim was an amazing fun game experience, one of the best I've had to date. Having said that, the game was also the buggiest game I have ever played. I got fairly far into the game before I encountered any bugs that I actually noticed up front but eventually I did, and then started hitting them every few days another one completely unreleated, and another and another. Many of them were minor in nature and not game breaking per se but annoying still. But eventually I started hitting terrible game breaking bugs and had to hit Google to search for help with them. With every single bug I encountered, I found tonnes of posts online about it with people seeking help for the same or similar issue, and most of them ultimately lead me to one of two huge Skyrim wikis that documented most of the game including known bugs with various quests etc. and if any solution to the problem was known they posted how to work around or fix it.
Fortunately for me, most of the game breaking bugs I encountered were fixable via going into the game's console and typing in a number of obscure commands or similar, possibly having to do some dinking around to get back to where I was or whatever. It really broke the immersion in the game and often got me frustrated or angry, but the game was awesome so my frustration waned as I went back to enjoying the game until the next major bug. One of the worst bugs I encountered was at the mage school in Winterhold or whatever it's called, where a battle between the mages and a dragon attacking the school resulted in the archmage that I needed to talk to to complete a quest getting killed and his body somehow magically getting thrown into the inside of the building walls at a location not reachable by the player so I could not talk to him nor even interact with his dead body. It was a rare bug that some people hit and others didn't, and I was one that hit it. Massive frustration. The only fix was to go back to an ancient 1-2 week old save game and lose dozens if not over a hundred hours of gameplay to redo the part that screws up and hope it didn't screw up again. It screwed up one more time for me, and another reload of a save I got past it, but what an ordeal. Then I had to make up all the quests and progress of the lost week or so's worth of gameplay. I was soooo pissed! :)
Anyhow, that kind of thing continued over and over again on almost a daily basis until I finished the game although most of them were fixed or worked around with console commands. Things like having to go kill a bandit chief in a quest to complete it, when I had already found and killed him before I had obtained the quest and the game didn't register he was dead. Had to go find where he was supposed to be, find his dead body, then issue a command in the game console to bring him back to life and instantly kill him to register the death. I could go on for hours and hours of all the Skyrim bugs I remember encountering, it was a nightmare. But... despite that, the game was amazing and I did eventually complete it. My final save games are still plagued with unfinished optional quests that had quest breaking bugs and other problems though, so I played the after game for a while and then retired the game without finishing every single optional quest.
I mention all of that only to contrast it with The Witcher 3. The Witcher 3 was a much larger game world and game IMHO according to all accounts, size of the maps etc. however in my own personal experience playing the original game patch version and the patches that came out while I was on my playthrough from release day up until about 6 weeks later I did encounter a handful of bugs, but most of them were silly graphical errors, floating heads and bodies in Novigrad, some Roach glitches and other odd things that were annoying but not game breaking. A very few number of crash to desktops, and my whole playthrough I only encountered one game breaking bug which was following Triss through the Novigrad sewers at one point she blocks the doorway you're both supposed to go through, telling you to "come on, lets go" or something like that but you can't because she's blocking the friggen way. I reloaded a savegame that was like 10-15minutes old and redid the sewers and didn't encounter the problem the next time. I'm not sure if I encountered any other cock-blocks in the game at all that were main-quest game breaking or not. I did encounter a few other side quest breaking bugs, but they were just the game not properly registering the quest I completed. One was something not registering me reaching a point in a lake on Undvik or something, that's still unregistered in my final save game I think unless a later patch fixed it (never checked). Don't remember the others. Most of the games bugs were minor in nature and about 1/20th as annoying as the multitude of bugs in Skyrim.
None of that will help your problem of course if you're experiencing a game breaker, but if anything I hope it gives some consolation that game breaking bugs in The Witcher 3 are seemingly very rare from many folks experiences and CDPR seems to have been quick to address many of them in the various patches they've released. Hopefully they continue to support the game into the future as well as they have to date and the issue you're having gets resolved though. I wouldn't want to hit it myself in my next playthrough.
Best of luck with finding a solution!
