


Others have found a better fix which has been posted on the page for the full version of the game, which I can confirm works on the free trial, so I'll post the steps here as well.
Basically you need to open the "FFXIV_BOOT.cfg" file and change the value on the "WebView2RuntimeInvalid" setting from 0 to 1, then save and restart steam (for some reason I actually had to restart the whole OS to get it to work). I also deleted the Microsoft folder the update added, though I'm not sure if that's necessary.
The report I saw said the config file was at:
/home/YOURUSER/.local/share/Steam/steamapps/compatdata/39210/pfx/drive_c/users/steamuser/My Documents/My Games/FINAL FANTASY XIV - A Realm Reborn/
Though for me it was actually at:
/home/YOURUSER/.steam/root/steamapps/compatdata/312060/pfx/drive_c/users/steamuser/Documents/My Games/FINAL FANTASY XIV - A Realm Reborn/
Not sure if that's because I'm still on the free trial or if it's due to using a different Linux distro. If nothing else you can always run a search your home folder for the config file I guess.
If you want to delete the Microsoft folder as well: from the folder with the config file nagivate up to the "drive_c" folder, then go in to the "Program Files (x86)" folder, it should be in there.

The problem seems to stem from how it tries to install the Edge Webview2 Runtime now. You can get around this by closing out the window that's installing it before it finishes (eventually one of the install windows should have an "X" in the upper right corner)-the game will then ask you if you want to launch it with a temporary display, which will actualy work.
If you tried to launch it and the runtime already finished installing, then you'll have to get it to install again so you can cancel it. The way I did this was to simply switch to an older version of Proton. Though this did mean I had to reconfigure all my hotbar/hud/other settings, since Square doesn't let you save/import those on the free trial, annoyingly.

no license
i registered for an account, logged into mog, checked that i did indeed have a free trial account, but errored out signing in saying i have no license to the game.

Luancher requires a long update that is prone to stop downloading. can be completed but takes alot of paitence
You can play using default proton but it will bork fmvs.

XL_SECRET_PROVIDER=FILED %command run --parent-expose-pids --parent-share-pids --parent-pid=1 --branch=stable --arch=x86_64 --command=xivlauncher dev.goats.xivlauncher
radial menu on left trackpad
40hz 8 TDP 1000 GPU Clock Frequency
dialouge text can be small at arms lenght and i have bad eyesight
plays as well as on pc
works perfectly just gotta mess with cotrols and gui to your liking

Must use xivlauncher if you didn't purchase FF14 via Steam

Launcher opens to blank screen with FFXIV Logo
I've tried everything, the current version of the launcher is borked for me.

Launcher performance is a bit low
Previous comments lacked the path to the correct FFXIV_BOOT.cfg. Steam created a 'My Games' folder in my home directory with this file -- but it was not the correct one. I found the one to edit in {yoursteampath}/steamapps/compatdata/312060/pfx/drive_c/users/steamuser/My\ Documents/My\ Games/FINAL\ FANTASY\ XIV\ -\ A\ Realm\ Reborn/FFXIV_BOOT.cfg
Changed 'Version 2' to 'Version 1' and 'Browser 2' to 'Browser 1'.

GloriousEggroll
This is the free trial version of FFXIV, which is exactly the same as the paid version, but I thought I'd leave a review for anyone who comes here. Game run excellently under GloriousEggroll, native Proton still currently has issues with the launcher, but runs once in game. For more info, checkout the main FFXIV page: https://www.protondb.com/app/39210