Issue Summary

When using the "New issue transition experience" in Jira Cloud, the fields such as 'Reporter', 'Assignee', 'Security Level' is visible during the transition, even if the user lacks permission to modify it. This results in an error when attempting to transition the issue. In contrast, the "old transition experience" does not display fields that the user lacks permission to modify, allowing the transition to proceed without error.

Steps to Reproduce

1. Add the 'Reporter' field to the transition screen.
2. Ensure the user does not have 'modify reporter' permission.
3. Attempt to transition an issue using the new issue transition experience.

Expected Results

The transition should proceed without error, similar to the old transition experience, which does not display the 'Reporter' field if the user lacks permission.

Actual Results

An error occurs during the transition because the 'Reporter' field is displayed, but the user does not have permission to edit it.

"Field 'reporter' cannot be set. It is not on the appropriate screen, or unknown," 

Workaround

Users can continue using the old transition experience, where the 'Reporter' field is not displayed if they do not have permission. This avoids the error and allows the transition to proceed smoothly.
You can toggle off the "New issue transition experience" in Jira labs.
Personal Settings > General > Jira labs > New issue transition experience