Pallettes remain editable after deleting the workspace

( Since August 29 pallettes of nightlies are not editable without having first created a workspace ).
To see the problem :

1 - Create a workspace (Edit> Workspaces> New ...)
2 - Then right click on a pallette and check "Enable Editing"

pallettes are now customizable

3 - Delete the workspace (Edit> Workspaces> Delete)

Expected result : pallettes are no longer editable
Result : pallettes are editable

Close the partition being not sufficient to prevent MuseScore that the workspace does not exist. To make effective suppression of the workspace must be closed MuseScore.