I have installed a single user Positions Desktop add-in for ArcGIS on my Win 10 machine. Process seems smooth and no problems were encountered. When starting ArcGIS 10.8 the Positions tool bar appears but when I click the icon to "Show Trimble Positions Desktop Administration Window" the icon "greys out" but that's it. Nothing else happens. Similarly clicking the toggle for desktop visibility causes the ico to grey but nothing else happens. No error messages, nothing. Any advice?