Description of problem: Whenever I attempt too select the "configure" option for the Cinnamon start menu, nothing happens and the configuration window never opens. While the configuration menu opens when running "cinnamon-menu-editor" in the terminal, non of the options do anything. Every time an option is selected, it outputs the following error:

Traceback (most recent call last):
  File "/usr/share/cinnamon/cinnamon-desktop-editor/cinnamon-desktop-editor.py", line 21, in <module>
    import JsonSettingsWidgets
  File "/usr/share/cinnamon/cinnamon-settings/bin/JsonSettingsWidgets.py", line 332, in <module>
    globals()["JSONSettings"+widget] = json_settings_factory(widget)
  File "/usr/share/cinnamon/cinnamon-settings/bin/JsonSettingsWidgets.py", line 313, in json_settings_factory
    class NewClass(globals()[subclass], JSONSettingsBackend):
KeyError: 'SoundFileChooser'



Version-Release number of selected component (if applicable):


How reproducible: It happens every time you attempt to right click and select "configure" on the Cinnamon start menu icon, and the latter happens everytime you attempt to run the start menu configuration program from the terminal with "cinnamon-menu-editor".


Steps to Reproduce:
1. Right click the Cinnamon start menu and select "configure"
2. Type "cinnamon-menu-editor" in the terminal and attempt to select any option
3.