instructure/canvas-lms · error

Invalid submission type

Error message

Invalid submission type

What it means

For student_annotation submissions, Canvas requires the assignment's annotatable attachment to be an annotated-document type (annotated_document? check); submitting with student_annotation when the attached file is not an annotation-capable document raises 'Invalid submission type'.

Solutions

1. Confirm the assignment's annotatable attachment is a supported annotated document type (PDF etc.) and re-attach if not
2. Verify the assignment's submission_types actually includes 'student_annotation'
3. Send the correct submission_type for the assignment (e.g. 'online_upload') if annotation was not intended

Example fix

# before
submit({ submission_type: 'student_annotation', annotatable_attachment_id: 42 })
# after
if assignment.annotated_document?
  submit({ submission_type: 'student_annotation', annotatable_attachment_id: assignment.annotatable_attachment_id })
end

const isStudentAnnotation = assignment.submissionTypes?.includes('student_annotation');
if (isStudentAnnotation && !assignment.annotatedDocument) {
  throw new Error('Assignment is not configured with an annotated document');
}

function acceptsStudentAnnotation(assignment) {
  return assignment != null &&
    Array.isArray(assignment.submissionTypes) &&
    assignment.submissionTypes.includes('student_annotation') &&
    assignment.annotatedDocument != null;
}

try {
  await submit({ submissionType: 'student_annotation' });
} catch (e) {
  if (e.message === 'Invalid submission type') {
    showError('This assignment does not accept student annotation submissions.');
  }
}

When it happens

Trigger: Submitting with submission_type 'student_annotation' while the assignment's annotatable attachment is not a supported annotated document (e.g. wrong file type attached, annotation feature set but attachment is an unsupported format, or assignment not configured as student annotation task).

Common situations: Teacher attaches an unsupported file type as the annotated document; assignment submission_types changed after creation leaving inconsistent config; API clients forcing student_annotation on a normal assignment.

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

• Invalid Attachment
• A course did not pass validation
• A # user did not pass validation (user: # , # : # , error…
• A maximum of 50 assessees can be provided at once
• A maximum of 50 assessors can be provided at once

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/15c6d9d7869b45eb. Report an issue: GitHub.

Appendix: source

Thrown at app/models/abstract_assignment.rb:2753

  ALLOWABLE_SUBMIT_HOMEWORK_OPTS = (SUBMIT_HOMEWORK_ATTRS +
                                    %w[comment group_comment attachments require_submission_type_is_valid resource_link_lookup_uuid student_id]).to_set

  def submit_homework(original_student, opts = {})
    raise "Student Required" unless original_student

    eula_timestamp = opts[:eula_agreement_timestamp]
    webhook_info = assignment_configuration_tool_lookups.take&.webhook_info
    should_add_proxy = false

    if opts[:proxied_student]
      current_user = original_student
      original_student = opts[:proxied_student]
      should_add_proxy = true
    end

    if opts[:submission_type] == "student_annotation"
      raise "Invalid Attachment" if opts[:annotatable_attachment_id].blank?
      raise "Invalid submission type" unless annotated_document?
      # Prevent the case where a user clicks Submit on a stale tab, expecting
      # to submit one set of work, only for another set to be submitted
      # instead.
      raise "Invalid Attachment" if opts[:annotatable_attachment_id].to_i != annotatable_attachment_id
    end

    # Only allow a few fields to be submitted.  Cannot submit the grade of a
    # homework assignment, for instance.
    opts.each_key do |k|
      opts.delete(k) unless ALLOWABLE_SUBMIT_HOMEWORK_OPTS.include?(k.to_s)
    end

    comment = opts.delete(:comment)
    group_comment = opts.delete(:group_comment)
    group, students = group_students(original_student)
    homeworks = []
    primary_homework = nil

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