Hi to the person that can offer me a possible solution,
I have a problem downloading updates on the GoG client in a sense that I CANNOT update Witcher 3! GoG client likes to troll harder than a 12 year old because everytime I'm updating W3 it will get to around 99.9% complete before giving me a "Server Error" , or some such error , and cancel the update AND I CANNOT FIND THE FILE IT'S BEEN UPDATING FOR THE PAST FEW HOURS IN ANY FILE ON MY COMPUTER SO I NEED TO RESTART THE ENTIRE UPDATE AGAIN ONLY TO 'MAYBE' GET THE ERROR AGAIN!! This is very frustrating because I have the slowest internet speed known to man, around 10-75 kbps, and when I have to download a 7.2GB update the last thing I want to happen is to hear is that I have to restart the download after 99.9% of it is complete. So can someone PLEASE explain WTF a "Server Error" is and how do i fix it - if it's a problem on my side - , also can someone explain where I can find the 7.1 GB I already downloaded for the past 4 days - if ofc the GoG (The name we shall not say, any longer ... *spit* *spit*) client doesnt delete it because logic bro.
Kindly (But not really)
A very very frustrated - forced - GoG user.

Can't you download the back up installer and install it manually?

Have you tried downloading the update directly from the GoG website?

Go to GoG.com & log in, then click on "Account" then "Library"
Click on the Witcher 3 & you will see a list of Game downloads,
in this list you want to download Patch 1.07(part 1 of 2) & Patch 1.07(part 2 of 2)
when both the files have finished downloading you need to launch part 1 of the downloads(this is the .exe file) & the update will be installed for you

I'm also having quite a few issues getting this update. I'm not sure when this happened, but both the GoG Downloader and the manual download links (in the library section of your account) I've found now point to a 1.01->1.07 update which of course is a fat lot of good when you've actually been keeping the damn game up to date :(

The text on the page hasn't been changed and still says 1.02 -> 1.07 though, so you only find this out once you've clicked the link.

there are a lot of issues with gog galaxy apparently. just use the website like i do. no issues at all :-)

Unfortunately my problems are *with* the website. I can see the only way I'm going to be able to get this update is by reinstalling the game from scratch :|