HTML Script fields on a form are not supported by the system property "glide.ui.dirty_form_support".
1. Log in as admin.
2. Go to "sys_properties.list".
3. Open the system property "glide.ui.dirty_form_support" and make sure it is set to true.
4. Go to any Notification record (e.g: "Incident commented for ITIL" /nav_to.do?uri=sysevent_email_action.do?sys_id=0d51edbac0a80164006963b000ff644e ).
5. Switch to the "What will contain" tab.
6. Type in the "Message HTML" field.
7. Right click on the header menu.
8. Select "Reload form". The expected alert message "Live site? Changes that you made may not be saved"[Leave] [Cancel] does not pop up and the form is reloaded.
This problem is under review and targeted to be fixed in a future release. To receive notifications when more information becomes available, subscribe to this Known Error article by clicking the Subscribe button at the top right of this form.