I found this on Reddit which may help.
Fixed!
"This error is caused by a broken wine prefix (usually). Delete the ~/.xlcore/wineprefix folder. On the deck, you need to go into desktop mode, open the file browser, and enable show hidden files. Then click the home icon on the left, open the .xlcore folder, and delete wineprefix."
Quote from Rankyn on the Discord, credit to him for this fix. Once you do this, launch XIVLauncher again and log in normally. The game will crash once, but WINE will come up and detect missing files. Let it install the missing files and voila, error fixed!
I know theyβve stated Steam Deck but the MacOS version also uses WINE to package up the game. So worth giving it a go.