The email notification form will not render when sys_properties glide.ui.escapte_text value is set to false.
Steps to Reproduce
Set the glide.ui.escape_text property to false.
Navigate to the notification (sysevent_email_action) list view.
The page displays 'The element type "br" must be terminated by the matching end-tag'.
Use one of the following workarounds:
Set the glide.ui.escape_text property system property to true (recommended).
Open the sys_ui_message form and in the Email Notification Form When to send Section Description, change the 2 <br> into <br />.
Related Problem: PRB1235296