Issue Summary

Cannot complete a sprint in a next-gen project if an issue added to a sprint is converted from Task to Subtask.

Changing the type of an issue from task to subtask is not clearing the sprint value of the subtask. If the issue is a task and it's added to a sprint, the sprint value still remains in the Jira database after converting the type to subtasks, but it isn't visible in the UI. The only way to identify this is by searching issues associated with the affected sprint

Steps to Reproduce

1. Create a next-gen project
2. Add issues to the project created
3. Start the sprint
4. Create another sprint and add issues to that sprint
5. Start that sprint
6. Convert one of the issues under this sprint to the sub-task issue type in the other sprint
7. Try to complete the sprint created in step 3.

Expected Results

The sprint gets completed.

Actual Results

The UI throws the error:

"Something's gone wrong
Sprint cannot be completed as there are incomplete subtasks on the following issues: XX-123"

Update:

• There are some cases where Sprints also fail to be completed silently, Jira redirects to the backlog without completing the Sprint.
• There are also some scenarios where the associated Sprint is from a company-managed board causing the same behavior

Workaround

Contact the support team to adjust the broken reference

1. Click on complete sprint to open the complete sprint modal in the project which has the issue
2. Open the network tab in the console
   1. Link on how to do it - https://support.happyfox.com/kb/article/882-accessing-the-browser-console-and-network-logs/
   2. For chrome F12 -> click on Network
3. Click complete the sprint from the modal
   
4. Look for a network request titled graphql look for one of these which has an error similar to the following "Sprint cannot be completed as there are incomplete subtasks on following issues: BT-2"
   
5. Following this search this issue using the search bar open the issue and there should be subtasks under this issue (in my screenshot above "BT-2)
   
6. Move the subtasks to your done status
   
7. You should be able to complete the sprint now
8. You can move the subtask statuses back to their original status