If you change the type of a menu option from submenu to something else, the submenu reference remains and will prevent uploading if the submenu references parameters that don't exist. This can happen in a normal workflow by duplicating and modifying an existing menu, or just by removing functionality from an existing avatar by repurposing the submenu control.

Reproduce steps:

On an existing avatar, create a control of type submenu. Reference an existing submenu (or make a new one) that controls a parameter that isn't on the avatar.

Observe on the SDK window that upload is prevented with the message:

"VRCExpressionsMenu uses a parameter that is not defined." This is expected behaviour.

Next, change the type of control you added from submenu to toggle.

Observe that the SDK still prevents you from uploading, as the submenu is still referenced, but the field is hidden from the user, as the control type is now toggle.

Requesting to have the submenu reference cleared when the control type is changed from submenu to something else.