Setting ECD as default editor for class files without source does not work correctly in Photon.

[RobertZenz]

Setting ECD as the default editor for class files without any source automatically seems to fail on Photon.

This can be easily corrected by user-interaction. Under "Window -> Preferences" select "General -> Editors -> File Association", from the list select "*.class without source" and set the "Class Decompiler Viewer" as the default editor.

[JacksonBailey]

Related StackOverflow post: https://stackoverflow.com/a/52811998/1858327