When (re-)creating a new Service Principal Name (SPN), you receive the following output:

$ ktpass -princ HTTP/${host}@REALM -mapuser ${user}@REALM -pass xxx -crypto AES256-SHA1 -ptype KRB5_NT_PRINCIPAL -out my.keytab

Failed to set property 'servicePrincipalName' to 'HTTP/${host}' on Dn '${LDAP_DN}': 0x32
Warning: Unable to set SPN mapping data
If user already has an SPN mapping installed for HTTP/${host}, this is no cause for concern
Password set failed! 0x00000032

The error probably occurs, because you have already registered the SPN HTTP/${host} for user ${user}.

Delete the existing Service Principal Name

Delete the existing SPN by executing the following comamnd:

$ setspn -D HTTP/${host} ${user}

Unregistering ServicePrincipalName for ${LDAP_DN}