When on version 1.01 IV2.31R3 clicking play on Fallout London makes it look like it is starting something/loading something but no window ever apears and after a minute or so it just stops. Tried to repair the install and to fully uninstall it and reinstall fresh, both didn't work. The only thing that fixed it was rolling it back to version 2.31_Revision2.

You definitelly want to browse this forum for articles describing various ways on "how to install FO London"

It makes huge difference

Some differ more, some less, but most are even very precise what to click AFTER the installation.

(For example: first run the launcher, setup your video settings, but DO NOT click "Play", just close the Launcher. Then run FO London exclusively via F4SE_Loader.Exe)

Said that, both the step-by-step installation makes difference, as well how the game is being launched does.

It worked with the older version and still does but the Fallout London patcher thing that is suposed to pop up doesn't (patch/launch)

I was using manual installation process (downloaded FO London and later also downloaded the patch file, installed both manually, hence I cannot comment auto-patcher)

But the manual installer did work well, despite I am using circa 6 extra mods (to mitigate frequent to-OS-drops) and also some edits in .INI files.

I am still launching the game via F4SE_Loader.exe.
And I am playing it outside Galaxy (which is troublesome on Linux)
But in general, there are plenty Win users, who followed similar process (made the older version run, then applied newer patch, and all was fine), so there is hope.