Transition - "cannot assign issue to nonexistent user

hristo.iliev

Hi , I am unable to move an open issue through my workflow. I keep getting an error of "cannot assign issue to nonexistent user". It seems that you have tried to perform an illegal workflow operation. If you think this message is wrong, please contact your Jira administrator."

Kian Stack Mumo Systems

@hristo.iliev, 

It seems that you have a post function on your workflow which was assigning the issues to a user that no longer exists.

Take note of the issue type/types where this is occurring, along with the transition where this is occurring. Navigate to Project settings > Workflows and edit the workflow tied to the issue type which was throwing the error.

Look for the specific transition which is failing, and click on it. A little box should pop up that looks like this:

 

Click on the Post Functions link and check to see if one of them looks like this

 

This user will likely be one that doesn't exist any more. Just remove this post function and save your workflow.