C# setting HPNAME not working

[pwned555]

I'm trying to update a few system variable in C# based on what button a user selects. I'm having some issues with the HPNAME system variable.

 

I set the variables like this:

Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable("HPNAME", HPNAME);
Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable("HPSCALE", HPSCALE);
Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable("HPANG", HPANG);

 

I'm trying to set HPNAME to GRASS, when I step through the code it is correctly trying to set HPNAME to GRASS however nothing happens and the system variable is never changed. When I manually change HPNAME to GRASS in the command line it works fine.

 

The other two system variables above are correctly changing values.

 

Are there any issues with changing HPNAME? I have tried hard coding GRASS as well to test but no success.

Autodesk.AutoCAD.ApplicationServices.Application.SetSystemVariable("HPNAME", "GRASS");

 

Thanks,

[Hippe013]

I tested your code and It appears to be working on my end. Using Civil 3D 2018.

[pwned555]

Stupid thing, needed to lock the document to be able to update some of the system variables. Everything is working now, thanks.