To resolve the issue, please validate user's DN in ADUC as well as go to hamburger menu, environments, select source environment, Details. Search for affected user and write down user's DN.
Then, go to menu, Workflows, select the workflow, Staging, Select. Click Next until wizard will show a list of Source OUs. Make sure that:
- OU, that user is a member of, is listed there
- double-click that OU and verify if an additional LDAP filter was specified for that OU. If so, verify that this LDAP filter is applicable for affected user