Issue Description

When you add a distribution group with an email address as the participants for a task and you do not resolve the group to users, enabling an escalation email for the task results in the workflow instance going into error state.

Error Message

The following error occurs: “The parameter ‘addresses’ cannot be an empty string. Parameter name:addresses”.


The fix is available in the following K2 versions:

K2 4.7 March 2018 Cumulative Update K2 Five (5.0) September 2018 Cumulative Update K2 Five (5.1) November 2018 Cumulative Update K2 Five (5.2) May 2019 Cumulative Update K2 Five (5.3)
X X X Fix Pack 23 Fix Pack 30
  1. Ensure you have the correct K2 version and/or Cumulative Update installed. See KB001893 to see what Fix Pack level you have installed.
  2. Download the latest Fix Pack using the links in the table above for the version you require.
  3. Install the Fix Pack to apply the fix.
  4. You will have to start a new instance of the workflow in error state.