Security.cfg file is corrupted after upgrade to 20.3 and unable to login to OC with few users.
UIM : 20.x
Root cause of the problem is wrong upgrade.
While upgrading, please do not uninstall the existing UIM and then install new version, point to the existing DB. As all ACLs and bus users will exist in security.cfg file not in DB.
With this upgrade path, the users and acls will be erased from security.cfg and existing users cannot login.
The right upgrade path, upgrade the existing UIM version without uninstalling.