Latest Steam Beta Update causes script to fail

[JetstreamLarry]

When using the Steam client Beta Update, the script errors out after the Getting Steam AppInfo for GMod... line, with the following message:

Traceback (most recent call last):
  File "GModCEFCodecFix.py", line 448, in <module>
  File "steam/utils/appcache.py", line 73, in parse_appinfo
SyntaxError: Invalid magic, got b')DV\x07'
[24599] Failed to execute script 'GModCEFCodecFix' due to unhandled exception!
Press Enter to continue...

Opting out of the Steam Beta Update allows the script to complete successfully.
According to this, it's due to changes to the format of the appinfo.vdf file in the latest beta.

[WinterPhoenix]

It’s gotta be fixed in the package we use for parsing appinfo.vdf for it to be fixed here.

Workaround is opt out of the Steam Client Beta.

See ValvePython/steam#462

[WinterPhoenix]

This has been fixed as of the latest release