Answer
Look for an ORA-00257 Archiver Error on the database side — this specific IAM symptom is most commonly caused by the database host running out of disk space to archive redo logs, which in turn prevents IAM's own certificate-related database operations from completing. This is a database/infrastructure issue rather than an IAM configuration problem, so check archive-log-related disk space and settings with your DBA rather than looking at IAM configuration first.