Revit cannot run the external application

[aislas (Alfonso Islas)]

Hello, I have just installed the pollination plugin for Revit 2023 and am receiving an error that was last addressed in 2021. I reviewed the solutions to those errors and I think since then the stated changes were implemented such that i the solutions might be outdated. Here is a screenshot of the error. Is the issue still potentially my anti-virus blocking a particular file?

[mostapha]

Hi @aislas,

This is most likely a conflict issue with another Revit Addin. It looks like an older version of Nlog is loaded.

Can you try to add an underscore before the Pollination addin name? See here for more information:

Installing Pollination 2.338.0 Revit Plug-in for Revit 2025

Thank you for debugging, @srojas92! Let’s see if I can find someone in their company to help us with this. I don’t know if I know anyone, but @ksobon might know someone who can help us. A quick update from one of the customers who has a similar issue: adding an underscore to the front of the Pollination.Revit.addin file will cause it to manifest before CTC tools which prevents the load error. CTC mentions they have already fixed this issue in the 25.3 or higher versions of their plug-in.

In the case of Revit 2023, the path to the file is C:\ProgramData\Autodesk\Revit\Addins\2023\Pollination.Revit.addin.

[aislas (Alfonso Islas)]

Hi @mostapha I think you were correct. I disabled the Pirros plugin and things are operating normally. Thank you!

[aislas (Alfonso Islas)]

Hey @mostapha I was needing to use both the pirros and pollination plugins (for separate projects) on the same version of Revit. I went ahead and modified the file name _Pollination.Revit.addin. This did allow me to load pollination, but when I attempted to use the model editor i recieved multiple engine errors :(. I have included a copy of my log to show these.
2025.11.19 10_02_16.812.log (74.7 KB)

When i renamed the file back to its original name without the underscore, the app ran smoothly again. Will I need to toggle between changing the file name each time I want to use pollination with other addins for now? Is there a more permanent fix I can use?

[mostapha]

Hey @aislas,

Thank you for sharing the logs. From what I can see the issue doesn’t have to do with renaming the package. You just need a few restarts to make sure all the necessary libraries are downloaded for the Model Editor. This is a one time action that happens after every installation.

To test this, can you rename the .addin file, and then try to open the Model Editor Desktop application? You should be able to use the Model Editor regardless of the name of the addin.

@antonellodinunzio and @mingbo, please correct me if you believe any of my assumptions here are incorrect.