syncrepl provider not working after upgrade to 2.4.26

[Nick Milas <nick@eurobjects.com>]

Hi,

I have a syncrepl provider v2.4.22 working fine (the only provider in 
our organization).

I upgraded with the same configuration to v2.4.26 and provider is not 
working (neither over ldaps: nor over ldap:). Otherwise connectivity is 
fine (with any ldap client) both with ldap and with ldaps.

I get (in all consumers):

Oct 17 21:21:32 vmail slapd[14621]: do_syncrep2: rid=111 
LDAP_RES_SEARCH_RESULT
Oct 17 21:21:32 vmail slapd[14621]: do_syncrep2: rid=111 
LDAP_RES_SEARCH_RESULT (53) Server is unwilling to perform
Oct 17 21:21:32 vmail slapd[14621]: do_syncrep2: rid=111 (53) Server is 
unwilling to perform
Oct 17 21:21:32 vmail slapd[14621]: do_syncrepl: rid=111 rc -2 retrying

How can I troubleshoot the issue further?

Current config on the provider is:

   overlay syncprov
   syncprov-checkpoint 100 10
   syncprov-sessionlog 100

and on consumers:

   syncrepl rid=111
            provider=ldaps://ldap.example.com
            tls_reqcert=never
            type=refreshAndPersist
            retry="60 +"
            searchbase="dc=example,dc=com"
            schemachecking=off
            bindmethod=simple
            binddn="cn=someuser,dc=example,dc=com"
            credentials="password"

Thanks,
Nick