(I thought I posted this but now can't find it so sorry if this turns into a double-post)
This is cut from the stdout console running --verbose.
Loading resource: res://Sounds/Main/Sound1.ogg
Loading resource: res://Sounds/Music/Sound2.ogg
ERROR: No loader found for resource: res://Sounds/Music/Sound2.ogg.
Sound1 loads ok. Sound2 does not.
I used a search tool called Everything that will search a drive instantly (don't know how they do that) and removed any reference to Sound2 on both of the drives involved, and any references or resources inside my project. I rebooted the machine to clear any Windows issue, then opened Godot and exported immediately without running.
The Windows console window now shows no awareness of Sound2, but now I get the same error on Sound1.
I even copied everything into a new folder and loaded as a new project after deleting all the .import files/folders. Same problem.