After upgrading the server dirsrv fails to start with a schema error.

Issue

• I receive the following error when trying to start dirsrv after our upgrade.

[root@directoryserver ~]# service dirsrv start
Starting dirsrv:
<instance>...[dd/mm/yyyy:hh:mm:ss -0400] dse_read_one_file - The entry cn=schema in file /etc/dirsrv/slapd-<instance>/schema/99user.ldif (lineno: 1) is invalid, error code 20 (Type or value exists) - attribute type automountInformation: Does not match the OID "automountInformation-oid". Another attribute type is already using the name or OID.
[dd/mm/yyyy:hh:mm:ss -0400] dse - Please edit the file to correct the reported problems and then restart the server.
[FAILED]
*** Error: 1 instance(s) failed to start