Issue Summary

• Dragging sub-tasks to status 'Done' in an Agile board (Either Kanban or Scrum project) will give error on IE 11.

Steps to Reproduce

1. Create a Kanban or Scrum Project
2. Create some issues and at least one sub-task.
3. Go to the Active Sprints/Kanban Board and drag a sub-task from any status to 'Done' (or whatever the name of the last column is for your scenario):
   

Expected Behavior

• The sub-task is transitioned to the status linked with the column where it was dragged (usually 'Done').

Actual Behavior

• The sub-task transition its status correctly, but shows an error:
  

Cause

• Unknown.

Workaround

• To use other web browser like Chrome or Firefox, where the issue is not present.

Notes:

• Tested with IE 11.726.15063.0, Update versions: 11.0.48 (KB4047206)