When running BESAdmin.exe /resignSecurityData we receive an error that EncryptedServerSigningKey file can not be found (indeed, there is no such file).
Also, if logging in as MO, no entries are seen in LDAP Directories, although there are entries in LDAP_Settings table.
we still got some error when add LDAP Directories : Unexpected server error: SignedDataVerificationFailure in data type ‘LDAP_SETTINGS’ object ‘17626’ attribute ‘pass’
After performing the database update steps, Did you logged to bigfix console using local opertors and performed the neccesary changes in ldap configuration?
It should work because same issue I was facing 2 months back and after following the link I was able to get rid of the issue.