GPTK Steam Can't open UI; steamwebhelper is not responding

After updating my MacBook Pro to Mac OS Sonoma, I've tried to install Apple's **G**ame **P**orting **T**ool**k**it (GPTK). I've followed the AppleGamingWiki guide . ---------- Unfortunately, after installing + starting Steam using these 2 commands, I get the error as shown below:

# Install
gameportingtoolkit ~/my-game-prefix ~/Downloads/SteamSetup.exe

# Run
gameportingtoolkit ~/my-game-prefix 'C:\Program Files (x86)\Steam\steam.exe'

Error: ---------- I came across [a github issue](https://github.com/Whisky-App/Whisky/issues/41) that suggested to manually start steamwebhelper.exe and steamservice.exe before starting steam.exe. I've tried that, but the same error occurs. Somebody else [suggested](https://github.com/Whisky-App/Whisky/issues/41#issuecomment-1585640483) to copy the config, registry.vdf and userdata files from the MacOs Steam to the Windows variant, again, the same error occurs. Another [suggestion](https://github.com/Whisky-App/Whisky/issues/41#issuecomment-1601086964) that didn't work was to launch Steam using these arguments: -allosarches -cef-force-32bit. ---------- Does somebody know how to resolve this issue?