After releasing for PlayStation 4 and Xbox One, patch 1.7 is finally available for PC, too. As it happened with the console versions, this patch has also a few collateral effects resulting in bugs and glitches. Many of those can be fixed with some workaround, in the wait of an official update by CD Projekt RED: first, make sure you have deleted every mods you might have previously installed looking at the patch0.bundle folder. Let's take a look, then, at those issues and some of the ways you can solve them.
Lower fps
Once applied, patch 1.7 causes noticeably lower fps on several GPUs, especially those of the Nvidia series 750Ti, GTX 770 and others. You can partially fix this by disabling the v-sync.
Achievements
Lots of achievements regarding Gwent, brawl + brawl master quests and horse races don't work properly anymore. There's no current workaround, unfortunately.
Game settings
This bug causes all of your game settings to be removed and restored to default each time you exit the game. To fix this, go to documents/witcher 3 and untick “read-only” in user.settings file: the game will be able to actually overwrite that file and save your settings.
Graphical issues
If you encounter GFX issues, verify game cache files via GOG Galaxy or Steam depending on the client you used to download The Witcher 3: Wild Hunt. This should work.
Rainy weather issue
This crazy bug consists in rain displaying also when you are inside houses outside Novigrad.
NPC animation glitches
Brooms, crates, bottles and other things are not displaying properly in the hands of NPCs when you encounter this bug.
Alternate look for Ciri
Among several issues known for the alternative look for Ciri, there is a smaller one that causes a graphical bug on her neck during cut-scenes. A small white line will appear there.
Save issues
Xbox One and PlayStation 4 players also reported some issues with saves, and these problems also appeared to a few PC gamers. There's no known reason for this to happen, but before deleting your saves try to verify game files or re-installing the entire game.
Stash bound to E key / Items disappearing from stash
This bug causes the game not caring about which is your stash key, bounding it to the E button. More rarely, this leads the items you stash to disappearing.
Money disappears
This has still to be confirmed but looks like there's a bug out there that causes money to disappear. Basically, you can't get more money. Reasons and solutions unknown at the moment.
Mouse sensitivity
Options don't display anymore mouse sensitivity. If you want to fix this, turn off hardware cursor or change mouse settings in control panel.
Gamepad movement settings reduced
With patch 1.7 applying, the movement settings were reduced for gamepads: they were four, now are only two.
Geralt disappearing when moving the camera
This very rare bug consists in Geralt disappearing each time you move the camera. Verifying game cache files could be the most appropriate solution.
Issues with weight
If you were encumbered in 1.6 and you still are in 1.7, as it should actually be, use the 90000 weight mod, which is compatible with the new patch. Drop an item and get it back if you are still encumbered after applying the mod.
Vernon Roche (An Eye For An Eye quest)
This bug doesn't allow you to speak with Vernon. Since you won't be able to progress further with the quest, this can be considered a game breaking bug, and the only solution is to load save before accepting the quest.
Closed City quest / Collect them all (Gwent)
Quest changes to Failed if you already completed it and if you complete it. No solution available at the moment.
Skellige's Most Wanted
This bug makes the Werewolf immortal, and there's no fix currently.
Ambassador Var Attre
If you decide to talk to him in Wyzima, but you haven't during your first visit there, beware: you will encounter graphical issues like missing NPCs, walls, etc.
Wild Hunt soldiers teleporting during the defense of Kaer Morhen
Looks like Wild Hunt soldiers have learnt how to teleport for small distances during the defense of Kaer Morhen. They will use this ability mostly when attacked or while leaving the NPC fight zone, making the battle even harder to complete.
MatchesCountError message appearing, game not starting
If the MatchesCountError prevents your game to start, delete dsound.dll in Witcher 3 directory (bin/x64). This is said to be caused by Dev console enabler mod.
Music tracks stop playing upon completion of Coronation quest
If you meet this bug, that prevents music to play after your complete the Coronation quest, fast travel and you will restore the proper order of things.
Ally NPCs very vulnerable (Black Pearl quest)
Sometimes allies can be very vulnerable, like in the Black Pearl quest, where they die after just one enemy hit. Check the workaround posted on the official forums of CD Projekt RED to fix this.
Baron's Sergeant is missing one VO dialogue when leaning against the wall
This bug is really strange, since the dialogue works properly when the character doesn't lean against the wall.
Price of Honor quest
The Price of Honor quest was already bugged before the patch 1.07 was issued and it was supposed to fix the bug, but failed. The solution is to load the game before starting the quest.
Master Armorer quest
Testing Yoanas and Fergus armor, baron's soldier just stands there, not fall down, when he is hit by a bolt. The animation won't start because of this bug.
Missing stashes
This bug prevents the game from spawning stashes in some areas. For example, you could meet it in Rosemary.
Arche Griffin body
When you kill arche griffin, you pick up his trophy but the head doesn't actually disappear from this body. This is a smaller bug that doesn't harm your game experience, anyway.
Triss Merigold Soldier Statuette's side quest
If this bug activates, you won't be able to give Triss the statuettes. The conversation will stop at a certain point, and you won't be allowed to complete the quest. There's no solution now.