instructure/canvas-lms · error · GraphQL::ExecutionError

Anonymous assignments cannot be posted by graded only

Error message

Anonymous assignments cannot be posted by graded only

What it means

PostAssignmentGrades rejects graded_only when the assignment is anonymous_grading (note: checks the boolean attribute, not the ? predicate). For anonymous assignments 'post grades' is all-or-nothing, so filtering to already-graded submissions is disallowed.

Solutions

1. Omit graded_only (or set it false) when assignment.anonymous_grading is true.
2. Post once for all students instead of incrementally for anonymous assignments.
3. Client-side: disable the graded-only option when anonymous grading is enabled.

Example fix

// before
postAssignmentGrades(input: {assignmentId, gradedOnly: true}) // anonymous assignment
// after
const gradedOnly = assignment.anonymousGrading ? false : true;
postAssignmentGrades(input: {assignmentId, gradedOnly})

const gradedOnly = assignment.anonymousGrading ? false : Boolean(gradedOnlyPref);

try { await post(); } catch (e) { if (/graded only/.test(e.message)) { input.gradedOnly = false; await post(); } }

When it happens

Trigger: postAssignmentGrades with input.graded_only=true on an assignment where assignment.anonymous_grading is true.

Common situations: Clients that default graded_only to true (e.g. reusing 'post grades to graded only' checkbox) while the assignment is anonymous.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• and cannot be used together
• and cannot be used together
• Anonymous assignments cannot be hidden by section
• Anonymous assignments cannot be posted by section
• Anonymous assignments cannot be posted by section

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/fb60414b1806e240. Report an issue: GitHub.

Appendix: source

Thrown at app/graphql/mutations/post_assignment_grades.rb:51

  def resolve(input:)
    begin
      assignment = AbstractAssignment.find_assignment_or_peer_review(input[:assignment_id])
      course = assignment.context
      sections = input[:section_ids] ? course.course_sections.where(id: input[:section_ids]) : nil
    rescue ActiveRecord::RecordNotFound
      raise GraphQL::ExecutionError, "not found"
    end

    verify_authorized_action!(assignment, :grade)

    unless assignment.grades_published?
      raise GraphQL::ExecutionError, "Assignments under moderation cannot be posted before grades are published"
    end
    raise GraphQL::ExecutionError, "Anonymous assignments cannot be posted by section" if sections && assignment.anonymous_grading?

    if input[:graded_only] && assignment.anonymous_grading
      raise GraphQL::ExecutionError, "Anonymous assignments cannot be posted by graded only"
    end

    if input[:only_student_ids] && input[:skip_student_ids]
      raise GraphQL::ExecutionError, I18n.t("{a} and {b} cannot be used together", a: "only_student_ids", b: "skip_student_ids")
    end

    visible_enrollments = course.apply_enrollment_visibility(course.student_enrollments, current_user, sections)
    visible_enrollments = visible_enrollments.where(user_id: input[:only_student_ids]) if input[:only_student_ids]
    visible_enrollments = visible_enrollments.where.not(user_id: input[:skip_student_ids]) if input[:skip_student_ids]

    submissions_scope = input[:graded_only] ? assignment.submissions.postable : assignment.submissions
    submissions_scope = submissions_scope.joins(user: :enrollments).merge(visible_enrollments)
    submission_ids = submissions_scope.pluck(:id)
    progress = course.progresses.new(tag: "post_assignment_grades")

    posting_params = {
      graded_only: !!input[:graded_only],
      section_names: sections&.pluck(:name)

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