Installation & Licensing

Posts: 18
Registered: ‎04-14-2009
Message 1 of 4 (273 Views)

Class not registered?

273 Views, 3 Replies
05-04-2011 12:00 PM

Okay, I know stay cool!  Had a fatal error message this morning while using AutoCAD 9 Architecture.  I uninstalled AutoCAD and reinstalled it from the original disk and SN.  Started the program and attempted to use the "Tool Palattes - Design" in the Design Workspace.  Received message "Unable to execute the tool.  Class not registered".  What is this and how do I correct it? When I reinstalled the program it seemed to load very slowly.  I do not know if the two are related.

Posts: 18
Registered: ‎04-14-2009
Message 2 of 4 (253 Views)

Re: Class not registered?

05-06-2011 11:15 AM in reply to: KONASLACKER

Here is the solution suggested by Autodesk.  Doing the repair did not resolve the problem but installing the latest update did work.  Many thanks to the rapid reply from those at the autodesk.


I understand that when clicking a tool in a tool palette within AutoCAD Architecture 2009, it shows the message "Unable to execute tool. Class not registered."

I am sorry to hear that you are having this trouble. Doing a repair of AutoCAD should fix the problem. The repair is done through Add or Remove Programs. If it does not help, then please do the following:

  1. Install the latest update for AutoCAD Architecture 2009:

  2. Switch to a different profile within AutoCAD and then back to the desired one. If you have your profile backed up as an ARG file, try deleting the existing profile and then importing it again.
  3. Repair the .NET Framework in Windows:
    1. Go through Add or Remove Programs and uninstall everything that has to do with Microsoft .NET, doing newest versions first.
    2. Download and run the .NET Framework Cleanup Tool. If errors occur in the utility, run it again until no errors occur.
    3. Download and install .NET 3.5 Service Pack 1:
    4. Download and install .NET 4.0:
    5. Reboot the computer.

Please let me know how this works out.

New Member
Posts: 2
Registered: ‎06-09-2007
Message 3 of 4 (136 Views)

Re: Class not registered?

12-12-2012 01:49 PM in reply to: KONASLACKER

Sorry, but NO, removing and cleaning .net from the computer, the running the .net reinstall programs, did nothing to fix the 'class not registered' problem.  Any other suggestions?

New Member
Posts: 2
Registered: ‎06-09-2007
Message 4 of 4 (132 Views)

Re: Class not registered?

12-12-2012 04:15 PM in reply to: jft

Now, since the above did not work I went searching for other's solutions to this pesky problem.  Below is what I found in an MEP forum posted by David B.  Now, if only I had not tried reinstalling AutoCAD several times previously, I would not be locked out because of 'too many installs'.  I bug Autodesk about this tomorrow.


"Been running across this error for several releases, all the way back to 2005. Usually it occurs when specific tools (such as the AEC Callout command, that creates sections, elevations, etc.) are not properly registered when the program is installed. Some users have success fixing this using a repair, but I didn't...and here's why I think that happened.

- ALWAYS install Autodesk products as an administrator. A quick way to do this is instead of just double clicking on the setup.exe file, right click on it and choose "Run as Administrator". Even though I've got admin rights on my Win7 notebook, it doesn't always work - so this guarantees it's installed with the correct rights.
- ALSO - use a CUSTOM install - to do this in 2012, you have to pick the AutoCAD MEP 2012 install package on the new installer - this expands the window to give you your options. I always do a custom install, adding Express Tools, and more importantly, the AutoCAD Architecture profile - that way I have all of the AutoCAD Architecture tools.

After wiping out my initial, "typical" install, and reinstalling, everything works fine...even an old dawg like me needs the shock collar once in a while...

Happy CAD'ing!

David B."

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