Issue Summary

When using the External System Import, selecting the Trello option, to import data from Trello, multiple errors occur related to user import.

Steps to Reproduce

1. Create a Board in Trello;
2. Create some lists with some cards on it;
3. Add users to these cards, come users can belong to a Jira instance, and some don't;
4. Go to External System Import in Jira, select the Trello option;
5. Follow the instructions to import the desired Board;

Expected Results

The import result with no errors.

Actual Results

Depending on the case, some errors are thrown. A couple of examples:

• If the user already exists in the Jira instance:
  Cannot create user X: User X with status InactiveDueToLicenseRolesEnabled was not found after creating them.
• If the user doesn't belong to the instance:
  Cannot create user Y: java.util.ConcurrentModificationException: com.atlassian.jira.crowd.embedded.ofbiz.UserNotFoundException: User Y does not exist
• Some users might lose their current permissions on the Jira instance, overwritten by the Trello import.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available