So I'm working on a python code to connect to ETABS API and extract and write information from/to the model. The issue I'm having is that the code wont run because it gives the following error: Error creating ETABS helper object: [WinError -2147221005] Invalid class string Here's an extract from the code I'm working with: import os import sys import comtypes.client AttachToInstance = False SpecifyPathETABS = True SpecifyPathSAP2000 = True ETABSProgramPath = R'C:\Program Files\Computers and Structures\ETABS 22\ETABS.exe' SAP2000ProgramPath = R'C:\Program Files\Computers and Structures\SAP2000 22\SAP2000.exe' #set it to the desired path of your model folder APIPath = R'~path to model location~' #full path to the ETABS model ModelPath = APIPath + os.sep + 'model.EDB' #create API helper object for ETABS try: helper = comtypes.client.CreateObject('ETABSv1.Helper') helper = helper.QueryInterface(comtypes.gen.ETABSv1.cHelper) except (OSError, comtypes.COMError) as e: print(f"Error creating ETABS helper object: {e}") sys.exit(-1) I've tried loading ETABSv1.dll into registry using regsvr32, but got an error.. guess it's not the correct file to load to registry. Don't know what else to try to fix this. Continue reading...