Answer:
Exit REVIT and RFEM. Then, restart your PC to ensure that all the services have been restarted. Try to run the import/export again. If the problem persists, please reinstall RFEM.
During the import/export between REVIT and RFEM, an error appears. No RFEM model is open; what can I do?
Exit REVIT and RFEM. Then, restart your PC to ensure that all the services have been restarted. Try to run the import/export again. If the problem persists, please reinstall RFEM.