When I start NEXUS in AutoCAD®, all I see is a Welcome screen and after that I cannot locate the NEXUS toolbar or menu.

Please start AutoCAD®, type CUI on the command line so that Customize User Interface dialog box is displayed. In the top left section, expand Partial Customization Files, and check if NEXUS is on the list and if it is marked as Unresolved.

If you have NEXUS on the list and it is marked as Unresolved, please right click on it and unload it. Click on OK to close the CUI dialog box and then close AutoCAD®. Use the NEXUS desktop shortcut to start it in AutoCAD® and confirm that now the NEXUS toolbar or ribbon is displayed.