This error is still present, so i hit the debug in roundcubemail and posted it here.
Regarding version, everything is latest version on RHEL7
May 17 10:06:21 killah roundcube: <q021jrab> C: Connect [127.0.0.1:389]
May 17 10:06:21 killah roundcube: <q021jrab> S: OK
May 17 10:06:21 killah roundcube: <q021jrab> C: Bind [dn: mail=tmihalicek@domain.org,ou=Users,domainName=domain.org,o=domains,dc=domain,dc=org]
May 17 10:06:21 killah roundcube: <q021jrab> S: OK
May 17 10:06:21 killah roundcube: <q021jrab> C: Search base dn: [domainName=domain.org,o=domains,dc=domain,dc=org] scope [sub] with filter [(&(&(enabledService=mail)(enabledService=deliver)(enabledService=displayedInGlobalAddressBook)(|(objectClass=mailUser)(objectClas$
May 17 10:06:21 killah roundcube: <q021jrab> Using function ldap_search on scope sub ($ns_function is ldap_search)
May 17 10:06:21 killah roundcube: <q021jrab> C: (Without VLV) Setting a filter of (&(&(enabledService=mail)(enabledService=deliver)(enabledService=displayedInGlobalAddressBook)(|(objectClass=mailUser)(objectClass=mailList)(objectClass=mailAlias)))(|(cn=*t*)(givenname=*$
May 17 10:06:21 killah roundcube: <q021jrab> Executing search with return attributes: array (#012 0 => 'cn',#012 1 => 'sn',#012 2 => 'givenname',#012 3 => 'title',#012 4 => 'mail',#012 5 => 'telephonenumber',#012 6 => 'mobile',#012 7 => 'facsimiletelephonenumbe$
May 17 10:06:21 killah roundcube: <q021jrab> S: 4 record(s) found
May 17 10:06:21 killah roundcube: <q021jrab> C: Search base dn: [domainName=domain.org,o=domains,dc=domain,dc=org] scope [] with filter [(&(=*t*))]
May 17 10:06:21 killah roundcube: <q021jrab> Using function ldap_list on scope ($ns_function is ldap_read)
May 17 10:06:21 killah roundcube: <q021jrab> C: (Without VLV) Setting a filter of (&(=*t*))
May 17 10:06:21 killah roundcube: <q021jrab> Executing search with return attributes: array (#012 0 => 'dn',#012 1 => 'objectClass',#012 2 => NULL,#012 3 => 'mail',#012)
May 17 10:06:21 killah roundcube: <q021jrab> PHP Error: LDAP: ldap_list failed for dn=domainName=domain.org,o=domains,dc=domain,dc=org. Bad search filter (POST /mail/?_task=mail&_action=autocomplete)
May 17 10:06:21 killah journal: ool inet: <q021jrab> C: Close
May 17 10:06:22 killah roundcube: <q021jrab> C: Connect [127.0.0.1:389]
May 17 10:06:22 killah roundcube: <q021jrab> S: OK
May 17 10:06:22 killah roundcube: <q021jrab> C: Bind [dn: mail=tmihalicek@domain.org,ou=Users,domainName=domain.org,o=domains,dc=domain,dc=org]
May 17 10:06:22 killah roundcube: <q021jrab> S: OK
May 17 10:06:22 killah roundcube: <q021jrab> C: Search base dn: [domainName=domain.org,o=domains,dc=domain,dc=org] scope [sub] with filter [(&(&(enabledService=mail)(enabledService=deliver)(enabledService=displayedInGlobalAddressBook)(|(objectClass=mailUser)(objectClas$
May 17 10:06:22 killah roundcube: <q021jrab> Using function ldap_search on scope sub ($ns_function is ldap_search)
May 17 10:06:22 killah roundcube: <q021jrab> C: (Without VLV) Setting a filter of (&(&(enabledService=mail)(enabledService=deliver)(enabledService=displayedInGlobalAddressBook)(|(objectClass=mailUser)(objectClass=mailList)(objectClass=mailAlias)))(|(cn=*tmihalicek*)(gi$
May 17 10:06:22 killah roundcube: <q021jrab> Executing search with return attributes: array (#012 0 => 'cn',#012 1 => 'sn',#012 2 => 'givenname',#012 3 => 'title',#012 4 => 'mail',#012 5 => 'telephonenumber',#012 6 => 'mobile',#012 7 => 'facsimiletelephonenumbe$
May 17 10:06:22 killah roundcube: <q021jrab> S: 1 record(s) found
May 17 10:06:22 killah roundcube: <q021jrab> C: Search base dn: [domainName=domain.org,o=domains,dc=domain,dc=org] scope [] with filter [(&(=*tmihalicek*))]
May 17 10:06:22 killah roundcube: <q021jrab> Using function ldap_list on scope ($ns_function is ldap_read)
May 17 10:06:22 killah roundcube: <q021jrab> C: (Without VLV) Setting a filter of (&(=*tmihalicek*))
May 17 10:06:22 killah roundcube: <q021jrab> Executing search with return attributes: array (#012 0 => 'dn',#012 1 => 'objectClass',#012 2 => NULL,#012 3 => 'mail',#012)
May 17 10:06:22 killah roundcube: <q021jrab> PHP Error: LDAP: ldap_list failed for dn=domainName=domain.org,o=domains,dc=domain,dc=org. Bad search filter (POST /mail/?_task=mail&_action=autocomplete)
May 17 10:06:22 killah journal: ool inet: <q021jrab> C: Close