@Jean-Marc ,
I’ve encountered an issue involving Revit 2025, pyRevit (v5.0.1), and Sofistik Bridge Modeler 2025. When launching Revit, I immediately receive the error shown in the attached screenshot, and the Sofistik add-in fails to load.
To investigate, I closed Revit and used a tool to selectively prevent each add-in from loading at startup. Through this process, I discovered that pyRevit appears to be the only add-in causing the conflict. When pyRevit is disabled, Sofistik Bridge Modeler loads and functions properly.
Have you heard about this issue before? If so, is there any known solution or workaround?
Can you post the details of the Error? That would help us diagnose exactly what’s happening.
Typical case of Loading sequence issue
When Revit loads add-ins and their dependencies, it does so in a single shared context. Basically, Revit loads add-ins alphabetically by their .addin filename, and the first add-in that references a particular DLL “wins” - its version gets loaded into memory. When the second add-in tries to use its version of the same DLL, Revit already has one loaded and won’t load another version, causing conflicts.
In your case, pyRevit and Sofistik Bridge Modeler are likely referencing different versions of the same DLL, and whichever loads second is running into trouble.
How to solve it
Quick fix
Rename either one of the .addin files to control the loading order. Add a “0_” prefix to make it load first, or a “z_” prefix to make it load last. Which one to rename depends on which add-in’s DLL version you prefer to be used.
Proper fixes
For add-in developers (not necessarily something you can do as a user):
Use Assembly Load Context in .NET to isolate dependencies (modern approach)
Package all dependencies into a single DLL to avoid conflicts
Use strong naming combined with binding redirects to handle version conflicts
Use unique namespaces for the assemblies to prevent collisions
None of these solutions are trivial to implement, which is why the filename-based quick fix is often the most practical approach.
Hope this helps! Let me know if you need any more details.
Thanks for this quick reply @Jean-Marc !
I don’t have any more details of the error, the Sofistik Bridge Addin just don’t show up when Revit project was open. The only detail I got when i click “see details” is:
