I've used GOG Galaxy with no issues for years. Then came Fallout London. I installed it and that froze my GOG Galaxy. It would open to a black window and do nothing. So, easy fix, uninstall and re-download. nope, now I get a corrupted source file error. chkdsk nothing, different downloads or versions won't work. Completely delete the folder and start from scratch, also no luck. Install something that isn't GOG Galaxy, yes worked. GOG Galaxy is the only thing i can't install.

Did you use the default installer, that needs to download components from the Internet, or the full installer for version 2.0.75.142*?

In case that doesn't help, the first thing to check is if your anti-virus is placing in quarantine any of the files created during installation.

The second thing worth trying is to install both vc_redist.x86.exe and vc_redist.x64.exe, then restart your computer.

If the problems persist, open a support ticket and attach a zipped up copy of your C:\ProgramData\GOG.com\Galaxy\logs folder.

* JSON link to the latest Windows and Mac versions, for anyone that might stumble onto this thread in the future. To make that page readable, you need to either use Firefox, enable the "pretty print" option in your browser, or install a browser extension like JSON Viewer.

What's the definition of insanity? Yeah, i tried again, just now, no changes, because i had already tried all the suggestions.
It worked, magically, no issues. Apparently, it just needed a day to rest. I mean, I get it, i could use a day of rest as well.

Thank you

I also tried to install GOG Galaxy again cause of Fallout London and the bugs are so weird.
Installer gets stuck on the last step after all the green bar is full, at the "configuring GOG galaxy" step, freezes, never closes, have to end task from task manager.
Tried both the web installer and the full version file. Same thing for both.
But the program actually installs in spite of the installer freezing.
And it opens when I log in windows because it is in the startup apps.
But if I close it I cannot open it again from the shortcut or the .exe file.... wat??