Overview#LDAP_UNAVAILABLE_CRITICAL_EXTENSION is an LDAP Result Code that Indicates the LDAP server was unable to satisfy a request because one or more critical extensions were not available.
Either the server does not support the control or the control is not appropriate for the operation type.
More Information#There might be more information for this subject on one of the following:
Add new attachment
Only authorized users are allowed to upload new attachments.