Hi., When customising the Workspace [ i.e. colouring menus and adding Panels to the Panel Dock ] on an Apple Mac, and then subsequently using File->Export, the Drop down list of Export formats are locked out [ i.e. I cannot go from PDF Print to any other format ]. To resolve I have to go back to one of the default Workspaces such as Essentials etc, and then the Dropdown can be accessed. This happens in all recent releases of InDesign including 2019. I imagine the root cause of the fault is more the colouring of the menus rather than docking extra panels to the right of the screen [ when customising the workspace ]