I am building the add-in for Navisworks Manage 2018. According to the instructions, I am setting the target framework of 4.6 for .NET. I have built TUM in a submodule and used it as a reference.
Aftr TUM, I have built ENGyn-Nodes, and ENGyn-performance profiler. But my build fails for Engyn.
Here is the error output:

Thanks and regards,
Jeetendra