Looks like https://www.reddit.com/r/supremecommander/comments/oo72rf/comment/h71cak1/ has the answer to this exact issue!

How do you set up FA? I did not have to provide any path -- just launch Steam on Linux and then try to launch supcom FA and failing.

Yeah I am using Proton 5 already to launch FA as per the linked guide. Just hoping someone who is currently playing on Linux can share their setup!

I have not tried running FA on Linux before so this is my first time trying.

Are you able to search for the log file (game_14814052.log)? It should contain more detailed info.

Hi! I recently tried installing Steam on my Ubuntu 18.08 Linux machine and followed the instructions under https://wiki.faforever.com/index.php?title=Setting_Up_FAF_Linux#Install_using_native_Steam . Things seemed fine and FA was launched but it immediately crashed with the following error message:

CD3DDeviceResources::DevResInitResources: Unable to load effect file /effects/cartographic.fx

Program : Z:\home\ponk\.local\share\Steam\steamapps\common\Supreme Commander Forged Alliance\bin\SupremeCommander.exe
Cmd line arguments : /windowed 1024 768

Callstack:
    unavailable.

Last 100 lines of log...

info: checking C:\users\steamuser\My Documents\My Games\Gas Powered Games\Supreme Commander Forged Alliance\mods
info: checking C:\users\steamuser\My Documents\My Games\Gas Powered Games\Supreme Commander Forged Alliance\maps
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\ambience.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\editor.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\effects.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\env.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\loc_us.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\lua.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\meshes.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\mods.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\mohodata.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\moholua.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\objects.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\projectiles.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\props.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\schook.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\skins.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\textures.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\units.scd', mounted as '/'
info: DISK: AddSearchPath: 'z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance', mounted as '/'
warning: Can't open lua file "Z:\home\ponk\.local\share\Steam\steamapps\common\Supreme Commander Forged Alliance\bin\..\Installed.Prefs"
warning: unable to load Installed.Prefs; using empty initial prefs
info: Hooked /lua/userInit.lua with /schook/lua/userInit.lua
info: Hooked /lua/globalInit.lua with /schook/lua/globalInit.lua
warning: SND: Error retrieving XACT COM interface. Unknown XACT Error
warning: SND: Error retrieving XACT COM interface. Unknown XACT Error
warning: SND: Error retrieving XACT COM interface. Unknown XACT Error
debug: Loading module '\000/lua/sim/buffdefinitions.lua\000'
debug: Loading module '\000/lua/sim/adjacencybuffs.lua\000'
debug: Loading module '\000/lua/sim/adjacencybufffunctions.lua\000'
debug: Loading module '\000/lua/sim/cheatbuffs.lua\000'
info: adding font file /fonts/arial.ttf
info: adding font file /fonts/arialbd.ttf
info: adding font file /fonts/arialbi.ttf
info: adding font file /fonts/ariali.ttf
info: adding font file /fonts/arialn.ttf
info: adding font file /fonts/arialnb.ttf
info: adding font file /fonts/arialnbi.ttf
info: adding font file /fonts/arialni.ttf
info: adding font file /fonts/ariblk.ttf
info: adding font file /fonts/arlrdbd.ttf
info: adding font file /fonts/butterbe.ttf
info: adding font file /fonts/vdub.ttf
info: adding font file /fonts/wintermu.ttf
info: adding font file /fonts/zeroes_3.ttf
debug: Loading module '\000/lua/keymap/keynames.lua\000'
debug: Loading module '\000/lua/keymap/keymapper.lua\000'
debug: Loading module '\000/lua/user/prefs.lua\000'
debug: Loading module '\000/lua/options/optionslogic.lua\000'
debug: Loading module '\000/lua/keymap/defaultkeymap.lua\000'
debug: Loading module '\000/lua/keymap/keyactions.lua\000'
debug: Loading module '\000/lua/options/options.lua\000'
warning: z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\effects.scd\effects\cartographic.fx: unable to compile effect: z:\home\ponk\.local\share\steam\steamapps\common\supreme commander forged alliance\gamedata\effects.scd\effects\cartographic.fx reason: unknown error

what is the best way to troubleshoot this? Thank you!