An issue has been reported in Reckon APS Tax 2019.5.0 where the Email address cannot be edited under the agent declaration session. This issue affects some 2019 Local File Master File (LCMSF).
The following error message is triggered:
LCMSF4 - Intermediary email - a Value is required
The declaration email will be made editable in APS Tax 2019.6.0.
If you're in a lower version, please enter email in tax agent console and populate the data via the integrity check window.