This also applies to making edits to emails. If you edit an email in an Engagement Program stream with Recipient Time Zone enabled within 25 hours of the next scheduled cast. The pre-processing is disrupted and the email will fail to send.
To avoid the issue please either
1) disable Recipient Time Zone
2) refrain from making edits to the Engagement Program streams or assets 25 hours before the next scheduled cast.
Who This Solution Applies To Customers using Engagement Program with Recipient Time Zone enabled