Issue Summary

Within Jira Cloud, when users are using the old issue view, it is not currently possible to create a subtask

Steps to Reproduce

1. Jira Cloud environments that have one or more subtask types issues in a company managed project
2. Navigate to an standard issue type (a non-subtask issue type)
3. From the ... menu (top right), select the "See the old view" (this appends the URL to have ?oldIssueView=true)
4. In the old issue view, go to the ... menu and choose create subtask.
5. Fill out all required fields and click the Create button

Expected Results

We expect a subtask to be created under the parent issue.

Actual Results

1. No issue is created
2. No visual indication of failure is shown to the end user
3. The browsers web console (developer tools) shows a HTTP 400 POST error

The below exception is thrown in the web console of the client:

Request URL: https://[examplesite].atlassian.net/rest/api/3/issue?updateHistory=true&applyDefaultValues=false
Request Method: POST
Status Code: 400 
Remote Address: [redacted]:443
Referrer Policy: same-origin
atl-traceid: [redacted]
:authority: [examplesite].atlassian.net
:method: POST
:path: /rest/api/3/issue?updateHistory=true&applyDefaultValues=false
:scheme: https
accept: application/json,text/javascript,/
accept-encoding: gzip, deflate, br
accept-language: en-US,en;q=0.9
{errorMessages: [], errors: {parent: "expected 'id' property to be a string"}}
errorMessages: []
errors:

Unknown macro: {parent}
parent: "expected 'id' property to be a string" 

When you examine the json payload being sent in that bad request .

{fields: {project: {id: "10000"}, issuetype: {id: "10005"}, parent: {id: 85533},…}, update: {}}
fields: {project: {id: "10000"}, issuetype: {id: "10005"}, parent: {id: 85533},…}
issuetype: {id: "10005"}
labels: []
parent: {id: 85533}
id: 85533
priority: {id: "3", name: "Medium",…}
project: {id: "10000"}
reporter: {id: "[redacted]"}
summary: "Test Atlassian Creation"
update: {}
 

You can see that the id value of the parent is being passed as an integer, but the system is currently restricting this to be a string for some reason. As a result, the issue creation fails, and the user cannot create subtasks in the old issue view right now.

Workaround

Using the new issue view will allow you to create subtasks without this problem.