The current offline Linux installer for The Crimson Court expansion for Darkest Dungeon seems to be broken. It’s much smaller than the previous build:
- darkest_dungeon_the_crimson_court_24839_28859.sh = 316MB (old build)
- darkest_dungeon_the_crimson_court_26186_81633.sh = 83MB (current build)

Installers for the base game and the other expansions have seen no significant change in size between these two builds, only the one for The Crimson Court is affected.

From a quick test it leads to placeholder content being shown in game, and I suspect more extensive testing would show more errors related to this expansion content.

I have also noticed that some dependencies are absent in the new installers causing the game to not start. In my case I noticed:

libc.so.6: version `GLIBC_2.38'
libm.so.6: version `GLIBC_2.38'

being required by '/Darkest Dungeon/game/_linuxnosteam/lib64/libSDL2-2.0.so.0'

While those dependencies could be installed separately this issue wasn't present in the previous Linux version with the filename "darkest_dungeon_24839_28859.sh".

You should not use the shipped build of SDL2, it has no reason to be there. Your system-provided build is going to be better maintained and probably have support for a wider range of setups.

If using ./play.it to generate native packages for Darkest Dungeon, this is already automatically handled: useless shipped libraries are dropped and replaced with dependencies on system-provided libraries instead.

Not sure it deserves to be called a "fix": GOG reverted the Linux installers to an older build of the game. One from 2018.

(not only the affected expansion, the whole game is back to the 2018 build)