External Tools - Add-in Assembly Not Found

[JasonLLINDNER]

On Friday I left the office and everything was fine but today when I was trying to check something in the model I kept getting the following popup warning when opening Revit. Any Ideas how to resolve? I tried the solution on this link  but it seems not even related. The folder they mentioned is already empty. I also checked the folder which is in the warning and it is also empty and cannot find the mentioned dll on any drive.

"Failed to initialize the add-in...does not exist" message appears when launching Revit | Revit 2020....

  

[RDAOU · Accepted solution]

@JasonLLINDNER 

All relate to Interoperability tools. Did you uninstall or update the addin in the past two days?

Also see following link - same topic as yours

 https://knowledge.autodesk.com/support/revit/troubleshooting/caas/sfdcarticles/sfdcarticles/Revit-Ex...

[JasonLLINDNER]

I did not uninstall or update. Maybe the IT did in the office but I can still see the tab for Interoperability in Revit so it is for sure not installed. 

[RDAOU · Accepted solution]

@JasonLLINDNER 

Then most probably they updated without first removing the older version of the adding. Not knowing which version you've got, I would suggest that you do the following

1. From windows control panel, Uninstall BIM Interoperability Tools for Revit (the images you posted say version 2020)

2. Go to this directory C:\%USERPROFILE%\AppData\Roaming\Autodesk\Revit\Addins\2020

   Remove the following files

   BIT.10.ClassificationManager.addin

   BIT.20.ModelChecker.addin

   BIT.30.COBieExtension.addin

3. Go to Autodesk Desktop App and install the latest available Addin listed there

Should fix it ...

[19fap2ar017]

In my case I'm using Revit 2025 and unable to use environment plugin as Jason mention to remove (%USERPROFILE%\AppData\Roaming\Autodesk\Revit\Addins\2025) files , but my folder is empty

[19fap2ar017]

how to resolve issue

[SameerAhamad]

I am not able to export NWC files from Revit as Export to NWC option is missing in Export Tool

[bzakar1]

i dont see the external tools