Error with ProDrawingFromTemplate ()

I don't see where you are setting the value of  template name,  line 56 and 57.   The actual name of the template.   You are probably using the sample code like I did, and in the sample (and in my code)  I call UsrDrawingCreate passing the actual name.   also see that TEMPLATE_NAME is the argument for my function. 

another thing:   see that your template.drw actually exists, in your start model directory, and the the config.pro option start_model_dir is set to the correct place.

code example: 
UsrDrawingCreate("ppart_vr");
return(0);
}

*==================================================================*\
FUNCTION: UserDrawingCreate()
PURPOSE: Creates a drawing for the current model.
\*==================================================================*/

int UsrDrawingCreate(char TEMPLATE_NAME[40])
{
ProError err, status;

I guess the “model” handle is invalid, try “solid_mdl” for testing in the function call to create the drawing via template, this must work if your current model is a solid.

Or use ProSolidMdlnameInit (ProSolidInit is depri) to init a valid solid handle. I thought a function for testing like IsSolid is available, but I’m not sure ( not at my desk😵‍💫).  In you case you need to extract the int type of the model on top, to feed that function and to get a valid result.