Currently master_levels_dir just defaults to "", without trying to autodetect the Master Levels either in the Steam directory or other common locations. Instead the user has to dig in the menu to "Wad options" and type by hand the path (if they remember it by heart).
Problem found: Steam lookup exists, but it can't look for secondary Steam libraries by this scheme. I have Master Levels installed on that location.
Other problems:
Even if path is set wrongly, Eternity will still offer to start a new game at that inexistent path, which will show as empty
No hint whatsoever that you've set an existing but wrong path (with no WADs).
Proposed fixes:
An option to just autodetect the Master Levels. This greatly depends on information about installed stuff.
A more graphical file browser
A text file viewer so you know what you're trying to play! Several wads are in sequence, such as the Dr. Sleep wads, and you'd like to know which is first.
Currently master_levels_dir just defaults to "", without trying to autodetect the Master Levels either in the Steam directory or other common locations. Instead the user has to dig in the menu to "Wad options" and type by hand the path (if they remember it by heart).