[SR-Users] Problems with dispatcher module | feature disabled

Hello! We noticed today an issue with the kamailio loadbalancing. Basically kamailio is not considering if an host is up or not, backends are set always as "FLAGS: AP" even if the host is down. I see this when the proxy starts : ERROR: dispatcher [dispatcher.c:768]: ds_warn_fixup(): failover functions used, but required AVP parameters are NULL -- feature disabled These the parameters I have set: # ----- dispatcher params ----- modparam("dispatcher", "list_file", "/etc/kamailio/dispatcher.list") modparam("dispatcher", "dst_avp", "$avp(dsdst)") modparam("dispatcher", "grp_avp", "$avp(dsgrp)") modparam("dispatcher", "cnt_avp", "$avp(dscnt)") modparam("dispatcher", "ds_ping_method", "OPTIONS") modparam("dispatcher", "ds_ping_reply_codes", "class=2;class=3;code=404") modparam("dispatcher", "ds_ping_from", "sip:proxy@sip.nexmo.com") modparam("dispatcher", "ds_ping_interval", 20) modparam("dispatcher", "ds_probing_threshold", 1) modparam("dispatcher", "ds_probing_mode", 1) modparam("dispatcher", "ds_hash_size", 10) modparam("dispatcher", "ds_hash_expire", 3600) modparam("dispatcher", "ds_hash_initexpire", 60) modparam("dispatcher", "ds_hash_check_interval", 10) modparam("dispatcher", "use_default", 0) modparam("dispatcher", "attrs_pvname", "$avp(carrierattr)") modparam("dispatcher", "setid_pvname", "$avp(carriergroup)") modparam("dispatcher", "flags", 2) I use 4.3.3, I think this issue started after upgrading from 4.3.1 but I can't say for sure. Can someone please give us some advices on this? Thanks Alessio