Summary

It's not possible to change an issue type from a custom sub-task type to the default sub-task type using the 'More' > 'Move' > 'Change issue type' wizard.

Steps to Reproduce

1. Create a new sub-task issue type
2. Create a standard issue
3. From this recent created standard issue create a sub-task ('More' > 'Create sub-task') and select the custom sub-task type you created on step 1
4. Open this newly created sub-task issue and try to change its issue type ('More' > 'Move' > 'Change issue type') and select the default Sub-task type and click 'Next'

Expected Results

You're able to change the issue type

Actual Results

An error message appears on the screen: The issue type selected is invalid.

Workaround

If you have the Issue Type field in the View Issue and Edit Issue screens you can edit the issue type from the view issue screen.