I thought this issue had been fixed in the last update, but it seems to still be broken again. Strange thing is using this for Blood and BuildGDX port works fine, but trying to use it for BuildGDX with Redneck Rampage and Shadow Warrior, as well as Quakespasm with Quake won't work at all. I can only get Redneck Rampage working half the time if I double click "play", but "play" will no longer work on the others.
Those that don't work also throw up the "Cloud Sync failed" warning, but I have cloud saves disabled globally on Galaxy, so i'm not sure why that warning is coming up.

Is this going to be fixed? Because not being able to use custom executable and arguments makes Galaxy kinda useless to me. And this feature has been on and off broken since I updated to Galaxy 2.0. Running the latest version of Galaxy btw.

All the games you mentioned have locked default launch parameters that can't be removed because they are grayed out. To make custom executables work now these grayed out launch parameters need to be gone, otherwise GOG Galaxy for whatever reason seems to always try to launch the game from the default parameters first no matter which executable is selected as "default executable".

GOG needs to find a better way to separate the default launch parameters from the custom ones. Maybe splitting the launch parameter section into "default "and "custom" with the option to activate/deactivate each would work better.

That's the thing though, a recent update before the Epic Games integration update seemed to fix that for me. Quakespasm and everything worked and the default parameters bug was gone, but the latest update re-broke it again.

It never did work for me. GOG Galaxy would always crash when I tried to launch Quake through my custom executable.

A game like The Ultimate Doom on the other hand worked and still works with GZDoom simply because there is no default permanent launch parameter set for it. My custom one is the only one listed and so Galaxy is not able to get confused about which executable to use.

I experience this issue with VTMR and I wonder: how do I make them "gone" when I can't delete them from the client?

Pretty sure I could find out by searching around a bit, but I wanted to add my +1 to this topic =D

You can't and that IS the problem that needs to be solved/fixed.

STILL needs to be fixed late 2021...

Bumping this...

STILL broken.