What happens to existing sub-tasks if i remove sub-tasks from the Issue Type Scheme?

[Simon Kofod]

I have an existing project with a default Issue Type Scheme. Epics, Stories, Tasks and sub-tasks. 

A lot of the existing issues are sub-tasks, but we would like to stop using those, and to prevent them from being used, by removing the type from the Issue Type Scheme.

But what happens to the existing sub-tasks? Will they stay, get deleted or?

I would like them to stay just for reference.

[Yogesh Mude · Accepted solution]

HI @Simon Kofod 

It will not allow removing without subtask ..if the project contains the multiple subtasks, You must have at least one valid sub-task issue type before removing the existing subtask from issue type scheme.