CSV import fails to set user picker fields (e.g assignee, reporter, custom field)

Issue Summary

CSV import (through issue navigator) fails to map the user for User Picker fields are set if using email address. One of the following errors appear for validation:

Even though the user is valid and email address is correct.

Steps to Reproduce

1. Set a user picker field/column in CSV file with email address. For example

   summary, description, owner, developer (custom field)
   Test issue, testuser, testuser, <EMAILID>
   

1. Assuming developer as the custom field for the user picker
2. Perform CSV import through Issue navigator (search issue page) > Import issues from CSV

Expected Results

Issue is created

Actual Results

• One of the following errors appear for validation:
  
  

Workaround

1. Import through Jira settings > System > External System Import > CSV Import
2. Or, Use AAID in the CSV file