waltc: Not sure how you missed it, but the answer to your question has been posted on the front page of this thread for weeks...;)
https://www.gog.com/forum/general_beta_gog_galaxy_2.0/how_to_keep_galaxy_v12_client_and_avoid_the_forced_v20_beta_update It works perfectly. Try it. In the future if you have a question--look around at the threads a bit--you might find your answer quickly.
obliviondoll: It's worth noting that as an unsupported third-party workaround that's reliant on GOG leaving defunct files on their servers and on the user making manual edits to config files outside of the app's settings, this isn't a proper answer. It is a valid one FOR NOW, but expecting GOG to actually provide this PROPERLY is still a valid request to be making.
Hah-hah...;) GOG doesn't willy-nilly leave its own files around by accident...! It's perfectly supported by GOG--it uses nothing but Gog's original Galaxy files, actually. Nothing is third party, btw. It's all Gog's own Galaxy files. The manual edits to the config file is nothing--it's simply using an option Gog's own executable supports--otherwise the command to ignore updates to Galaxy would not function at all, of course--and we'd all be forced to update to 2.0 whether we liked it or not.
You don't seem to understand that if GOG didn't want people using the 1.2.xx version of Galaxy anymore then you wouldn't be able to use it at all as all the supporting files for it would be gone. This
is Gog's "proper response" to your query--it appears it is all the response GOG is going to make.
It's perfectly supported--upgrades work fine, just as they always have, etc. GOG wants its users to be able to use what they feel comfortable with--which is why the Galaxy 1.2.xx works without problems. If GOG didn't want that--we wouldn't even be able to install the 1.2.xx version of Galaxy through any means at all.
So don't be scared of the simple-as-pie workaround that allows you to use Gog's
own, original Galaxy 1.2.xx. It's not a hack and it won't bite...;) It's what's known as a "work-around," that's all. Again, evidently this is the only "response" Gog is going to give any of us who want to stay on 1.2.xx until the serious bugs are ironed out of 2.0. Use it or not at your pleasure--but don't be afraid of it. It works fine--if it didn't I wouldn't use it myself.