When I start GuideSIGN in AutoCAD® all I get is a Welcome screen, and after that I cannot locate your toolbar or menu.

Please start AutoCAD®. Then type CUI in the command line so that Customize User Interface dialog box is displayed. In the top left section, expand Partial Customization Files and check to see if GuideSIGN is on the list and if it is marked as Unresolved. If you have GuideSIGN on the list and it is marked as Unresolved, please right click on it and unload it. Click on OK to close CUI dialog box and then close AutoCAD®®. Use the GuideSIGN desktop shortcut to start it in AutoCAD®® and confirm that now the GuideSIGN toolbar is displayed.