Fix: The fix (for me), in short, was to do a fresh install of the game from the Galaxy client itself, launch the game directly then launch it via the client.
Hey. Sorry I don’t have a solution but I’m just posting to say I’m in the same position. It gets to 97% and then gives the error about not having write access to the disk. I installed via this: The Witcher 3: Wild Hunt - Game of the Year Edition - Lutris
I had originally copied the game files over from a Heroic Launcher install (which didn’t work properly) and so I thought it might be something to do with that. I’ve deleted all of the game files and am now trying to download & install it fresh with Galaxy instead just to rule this out.
The issue is obviously with Galaxy but I’m not sure how we would go about fixing it to be honest. Keep an eye on the Galaxy installer page & script for updates as someone maintaining it might add a fix to it: GOG Galaxy - Lutris
If you make any progress then please post back; I’ll do the same
Edit: By the way, what is the point of connecting GOG on the sidebar in Lutris? I can’t really figure out its purpose…
Edit 2: Ok. After doing a fresh install of the game with the Galaxy client, it actually appears to have installed fully. I’ve also tried verifying the files and it looks like that might’ve worked too. I’m having trouble launching the game though. I had a C++ error to do with the Galaxy client so I’m going to investigate that now…
Anyway, I’d recommend doing a clean install of the game with Galaxy as that might do the trick.
Edit 3: I keep seeing ‘Failed to rebuild jump list’, whatever that means…
Anyway, I’ve changed the exe that Lutris uses to ‘Launch The Witcher 3 - Wild Hunt - Game of the Year Edition.lnk’ instead of launching the Galaxy client. The game launches now so that’s cool. However, without running the Galaxy client, I don’t think the game is going to get updated this way so it’s just a workaround really.
I do use a virtual desktop for this game so I suppose one way might be to have Lutris load the Galaxy client to see if it finds game updates, then launch the game via the shortcut placed on the virtual desktop. That’s probably the best compromise for now.
Edit 4: Now it seems I can launch the game from the Galaxy client. Maybe it just needed to be launched directly first before it’d work this way.
So that’s the game & Galaxy client working for me. The fix, in short, was to do a fresh install of the game from the Galaxy client itself, launch the game directly then launch it via the client.
I hope that helps.