When an Email step contains an empty value in the TO line of the recipient mail, the workflow will go into an error state and will not continue.
The following error occurs and is visible in K2 Management: “SourceCode.Workflow.Shapes.Execution.Mail.EWS: Exchange error code: ErrorInvalidRecipients Exchange error: Microsoft.Exchange.WebServices.Data.ServiceResponseException: At least one recipient isn't valid., A message can't be sent because it contains no recipients”.
The fix is available in the following K2 versions:
|K2 4.7 December 2019 Cumulative Update
||K2 Five (5.0) December 2019 Cumulative Update
||K2 Five (5.1) November 2018 Cumulative Update
||K2 Five (5.2) May 2019 Cumulative Update
||K2 Five (5.3) April 2020 Cumulative Update
||K2 Platform Classic (5.4)
||Fix Pack 37
||Fix Pack 42
||Fix Pack 7
||Fix Pack 1
- Ensure you have the correct K2 version and/or Cumulative Update installed. See KB001893 to see what Fix Pack level you have installed.
- Download the latest Fix Pack using the links in the table above for the version you require.
- Install the Fix Pack to apply the fix.
The fix logs the response code in the Host Server log and allows the workflow to continue even though the email is not sent.