Hello! Hopefully I'll be able to help you.
First, have you downloaded anything recently, such as the preset sync or anything out of the ordinary for the game? Or did the presets suddenly stop working?
Check to make sure all the presets you have of your friends are going into the Presets folder and not my_presets. If you have preset sync installed, I would uninstall, then reinstall.
Also, could you send me a screenshot here of what it looks like when you try and go to LC? Does the game crash, is the screen black, or anything else? Please let me know so I can assist.