No Such Attribute: Entry cn=schema cannot be modified because the attempt to update attribute objectclasses

Question

I am facing this issue while trying to upgrade Forgerock OpenAM from 13.5.2 to 14.6.4. Can anyone help as to what is the cause for this error. Does it require any changes to be done from OpenDJ side?

 Thread[http-bio-8080-exec-2,5,main]: TransactionId[cb42ba57-6658-42db-a5c5-d2b8ac630453-30]
ERROR: An error occurred while processing /WEB-INF/template/ldif/sfha/cts-add-multivalue.ldif
org.forgerock.opendj.ldap.ConstraintViolationException: No Such Attribute: Entry cn=schema cannot be modified because the attempt to update attribute objectclasses would have removed one or more values from the attribute that were not present:  ( 1.3.6.1.4.1.36733.2.2.2.27 )

I see that the /WEB-INF/template/ldif/sfha/cts-add-multivalue.ldif below content

dn: cn=schema
changetype: modify
add: attributeTypes
attributeTypes: ( 1.3.6.1.4.1.36733.2.2.1.136 NAME ( 'coreTokenMultiString01' ) DESC 'General mapped multi value string field' SYNTAX 1.3.6.1.4.1.1466.115.121.1.15  X-ORIGIN 'ForgeRock OpenAM CTSv2' )
attributeTypes: ( 1.3.6.1.4.1.36733.2.2.1.137 NAME ( 'coreTokenMultiString02' ) DESC 'General mapped multi value string field' SYNTAX 1.3.6.1.4.1.1466.115.121.1.15  X-ORIGIN 'ForgeRock OpenAM CTSv2' )
attributeTypes: ( 1.3.6.1.4.1.36733.2.2.1.138 NAME ( 'coreTokenMultiString03' ) DESC 'General mapped multi value string field' SYNTAX 1.3.6.1.4.1.1466.115.121.1.15  X-ORIGIN 'ForgeRock OpenAM CTSv2' )

It would help if anyone can explain the error so that I can debug more on this.