When a similar problem is encountered, the program does not report an error, and an error is reported when opening revit to call. It is considered that the relevant package is not loaded in the nuget management package or the version is inconsistent.
Solution:
1. Tools in Vs -> NuGet Package Manager -> Nuget package management solution
2. Search for presentationframework in the browser, select the corresponding package and click
3. The items to be updated will be automatically displayed on the right (generally, the items to be updated will be automatically selected by default), select the corresponding version, and click Install
4. Regenerate after the update is complete, and the problem is solved.