Error -200 when running Rhino Inside async

Hey guys,
I’m trying to run Rhino Inside async from a C# program, but keep getting the -200 error shown below:

Running the program sync however works as expected:


But as soon as I try something similar to this:

Task.Run(() => {

I get the -200 error. Any clue?

My rhino interfacing code is very much similar to this project and I’m on the latest WIP (7.0.19134.10505, 5/14/2019). Happy to provide more details if that helps.


Are you trying to run rhino with or without UI? Maybe some sample code of what RunRhino does would help

Hey Steve,
I’m trying to run rhino headless, i.e. without UI.

Sample code of RunRhino can be found in the sample project I linked. More specifically, check out AssemblyInitialize in this class.

Many thanks!