Copy/Paste/Edit of my existing comment buried inside this topic for better visibility:

I noticed the Update prompt mentioning "Beta", despite me having unchecked the participate in Beta checkbox in Galaxy 1.2 settings, and the prompt had me chose between "Update" and "Update later". That's pretty much Microsoft newspeak for "Yes" and "Yes". And I haaaaate it, so much.

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WARNING: Once you've received this popup, the next time you restart Galaxy, you will be forcibly updated to the v2.0 BETA.

If you closed (quit) Galaxy after the prompt, DO NOT start a GoG game through the start menu shortcut. Doing so will start Galaxy first, which will then in turn update to v2.0 BETA. Starting the game EXE directly, or with a manually created shortcut, won't start Galaxy.
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Triggered by this, I did the research and, sure enough, the forum is full with absolutely fair outrage about it. Reading about how the client is, effectively, still very much a Beta, only confirmed my apprehension to update.

So I clicked "Update later", then went ahead and disabled autostart, added "/runWithoutUpdating" to the shortcut, made a backup of the folders, then chopped off any and all files and folders that could be connected to the already downloaded update. In particular, I removed...

C:\ProgramData\GOG.com\Galaxy ...
... \redists\GalaxyUpdater.exe
... \autoupdate
... \autoupdate-verified
... \temp\desktop-galaxy-updater
... \selfupdate.json

If anything breaks, I'll try to restore from my backups. I refuse to use a half baked, clu(s/t)terfuck of a client, especially when it's being forced. MY machine, MY realm, GTFO.



Extremely disappointed with GoG right now. I've been with them from the early days and never ever in my entire life accepted or installed Steam, still remember a friend of mine showing it to me when it was new back in the day, and I hated it. It was such a baffling concept to me, "why would anyone, ever"... and here we are.

So, thanks GoG, I hate it.


*Addendum:
Out of curiosity, I exchanged the GalaxyUpdater EXE with the Windows Calculator EXE, just to see how often it would be called. The Calculator popped up a LOT. I deleted it after half a day, but I had to close the calculator about 4 times or so.


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tl;dr Checklist

To downgrade v2.0 to v1.2:
In case the update already happened, all you can do is...
1) uninstall Galaxy, and reinstall v1.2 from an old setup (Link: hosted by GoG).
2) DON'T let Galaxy start automatically after the setup (untick the box).
3) Then, before you start Galaxy, follow the other steps below.

*Mac OSX Galaxy 1.2.x addendum for this section, thanks to:
Furthermore, it's worth mentioning:

After you're done with all of it, you may have to import each of your games again, if you installed them to a custom path (which I did) rather than the default Galaxy suggested path. This is an annoying manual procedure and takes a ton of your time, especially if you have a few modded games, which may be validated and "repaired" (broken) when importing them in this way (which I have, and had happen to me - Fallout New Vegas, I think it was). You may want to backup-copy these games in their entirety (whole folder), and paste that copy back over the real game folder after Galaxy is done... "repairing".



To cleanly disable updates of your v1.2 Galaxy, do the following:
0) Recommended: Make a backup first (ZIP the folders, put it somewhere in case you need it later)

1) Delete C:\ProgramData\GOG.com\Galaxy\redists\GalaxyUpdater.exe
2) Add "/runWithoutUpdating" to the Galaxy shortcut
- Right click short cut, properties, "Target" box
- append a space and "/runWithoutUpdating" at the end (without quotation marks)
3) Disable Galaxy autostart in settings

Should be fine now, but there may be some setup files already downloaded and "waiting" to be installed, which will never happen now, thus it's just dead weight on your harddrive. If you want to clean that up...

4) Optional - Clean-up: Delete...
Inside of C:\ProgramData\GOG.com\Galaxy ...
- ... \autoupdate
- ... \autoupdate-verified
- ... \temp\desktop-galaxy-updater
- ... \selfupdate.json

*Mac OSX Galaxy 1.2.x addendum for this section, thanks to:
( ^ That's not for Windows! MacOS only. ^ )

5) Unrelated to update, but if you want to clear some space while we're already here...
- delete the contents of the \logs\ folder (mine was 600MB in size, jeez).
- after a few days, if everything works fine, you may delete the backup ZIPs. I'd keep them, tho.

6) Make your voices heard by voting in this community wishlist topic: Allow users to stay with Galaxy 1.2
And signal boosting: Open letter to GoG

Thanks for the tip, I hate 2.0 too

BTW, I just looked at my msconfig (still win7) and the autostart for gog galaxy is in HKEY_CURRENT_USER\Software\Microsoft\Windows\Current\Run\ under "launchOnStartup (data value being the location of GalaxyClient.exe followed by /launchViaAutoStart
So I suppose if I were to add /runWithoutUpdating I should be able to re-enable Galaxy's autostart without the risk of it being win10updated ?

edit: nope, the calculator just popped... Next time I'll try by replacing instead of adding...
edit2: didn't work either. now replacing the whole thing by the shotcut's target box's content, quotation marks included
edit3: nope.... ok, you know what ? I'll just do what I did with skype's updates: new text file, rename the .txt into GalaxyUpdater.exe, paste it in redists, set as readonly so that it can't be replaced easily by another program, and good luck updating anything with that

edit4 because it's better when writter properly:
1/ create a new .txt file somewhere (like, on your desktop), and rename it into GalaxyUpdater.exe (change file type: yes)
2/ open go to ProgramData\GOG.com\Galaxy\redists\ and replace the old GalaxyUpdater.exe with your fake one (you can copy the old one somewhere else or rename it it you want to make a backup)
3/ open the new GalaxyUpdater.exe's properties (right clic) and check the "read only" box so that it won't be overwritten (gog shouldn't be as paranoïd with his own files as skype was, but just in case...)
4/ (optional) clench your fists, raise your middle fingers, and shout "update that !"

make your own updater file is more helpful answer than 'run withoutudating... at least for Windows 10 users

Not really. GOG doesn't require there to be a file in that location to not update and to run fine. If you create a blank file that causes an error because it's not a valid .exe file, you'll get that error message every time GOG tries to access the file (multiple times a day). If you don't have a file there at all, it doesn't do anything.

While the Galaxy 1.2 installer is still hosted by GOG, I think someone should make a mirror in case it ends up being actually taken down.

I've seen a Mega link with the file in it already, floating around somewhere in these conversations...

1, legal issues
2, even if you keep a backup of the exe [which of course you should] it still just goes to gog server for downloading the files

Dunno about 1 (I guess it depends on jurisdiction), but in the case of 2, I think the installer contains the required files to use the client, and the rest is grabbed from GOG's servers.

More than that, most users who weren't already using Galaxy 2.0 are explicitly OPTED OUT of beta testing, so they're not just forcing it without our request, but directly against a promise not to do so.

Thanks for the guide BlackSun!
I was surprised by the forced update to version 2.x beta as well, it looks terrible and feels completely unfit!
Worst move GOG ever made!

Tanks, BackSun for the guide.

Uninstalled v2 and reinstalled 1.2 - applying the "trick" before opening it.
Everything works again. Just had to rescan my games folder with the built-in function and they were all back in again.

Thank you! Saved me a lot of time!

Link to the Mac OS installer:

https://content-system.gog.com/open_link/download?path=/open/galaxy/client/galaxy_client_1.2.67.47.pkg

Seems to work fine on 10.15 Catalina. Reinstalled right on top of the crap that is 2.0. I have my old view of my library again...sorted by purchase date and with my tags showing.

So, I installed the old version in D rather than C but none of the items noted below appear in any of my folders on D.

Inside of C:\ProgramData\GOG.com\Galaxy ...
- ... \autoupdate
- ... \autoupdate-verified
- ... \temp\desktop-galaxy-updater
- ... \selfupdate.json

In my C drive there is a Gog folder but none of these items appear in there either. I don't even have a programData folder in C. When I search on redist it appears as _redist, _redist appears in Dependencies and dependicies-temp but there is no Galaxyupdater.exe in either of them. There is not a selfupdates.json either.

I have made the shortcut with the amended target. So let's see what happens. Just strange I have none of those files.