create_course_assignment() returns error

[n8craig]

New rcanvas user. The library works well to get gradebooks. However, I encountered an error trying to create assignments.

rcanvas::create_course_assignment() returns the following error:

Error in canvas_query(url, args, "POST") : Unprocessable Entity (WebDAV; RFC 4918) (HTTP 422).

Not sure if this is related to the canvas_url() changes mentioned in other issues.

[astraetech]

Same here but for the grade_submission function.

[cmgray00]

Using version 0.9.3, create_course_assignment() returns the following error:

Error in canvas_query(url, args, "POST") : Not Found (HTTP 404).

(Note that I can successfully perform get_course_items() and some other things.)