If you have licensed LiveLink™ for Revit®, the installer registers an add-in for Revit Architecture. When the add-in is loaded a tab called COMSOL Multiphysics appears in Revit Architecture. The COMSOL Multiphysics tab will not appear if the add-in cannot be loaded by Revit Architecture. This can happen if, for example, the COMSOL installation is moved to a different location. To restore the add-in you can reinstall LiveLink for Revit.