Symptoms

The parameter 'addresses' cannot be an empty string. Parameter name: addresses
 

Diagnoses

Client have email escalation, email will be sent to the Destination users, many users are no longer in this company, that's why they get this error because the users who left the company still assigned as destination user and they don't have emails in our Identity table.
the client is listing the destination users from SQL table.
 

Resolution

We managed to solve this issue during a web meeting with the client, they had 37 pages of error instances and if you apply GoToActivity it will take long time,We Applied a quicker way to retry all the error instances in one time:


we edited the email escalation by unchecking the recipient (Destination users) and specify the email by using the same SQL table to get the user emails using the same criteria used to get the destination user.