http_process_state_client_drain error logged

Hi Everybody,

we recently updated our LTM to 11.6.0 hf1. after this operation, similar log entries have been found many times:

balancertmm[15437]011f0007http_process_state_client_drain - Invalid action:0x1130a1 (Client side: vip=/Common/Wpad-http profile=http addr=xxxx port=80 rtdom_id=0 client_ip=yyyy)

the virtual server is a simple HTTP server with an irule linked that distribute different wpad files based on client IP network.

the irule code is similar to this:

when HTTP_REQUEST {

    set settings [class lookup [IP::client_addr] wpad_subnets_classes]  

    if { [HTTP::uri] equals "/wpad.dat" } { 
        switch -glob $settings {

            "GERMANY" {
                log local0.info "[IP::client_addr] will have Germany Settings"                 
                HTTP::respond 200 content [ifile get GERMANY.wpad.dat]
            }

            "BRASIL"  {
                log local0.info "[IP::client_addr] will have Brasil Settings"                  
                HTTP::respond 200 content [ifile get BRASIL.wpad.dat]
            }

            "DIRECT" {
                log local0.info "[IP::client_addr] will have Direct Access"    
                HTTP::respond 200 content [ifile get DIRECT.wpad.dat]
            }

            "VPN" {
                log local0.info "[IP::client_addr] will have VPN Settings" 
                HTTP::respond 200 content [ifile get VPN.wpad.dat]
            }

            default {   
                log local0.info "[IP::client_addr] will have default settings (Italy)" 
                HTTP::respond 200 content [ifile get ITALY.wpad.dat]
            }

        }
    } else {
        log local0.info "[IP::client_addr] rejected. Requested wrong URI: [HTTP::uri]"                 
        reject
    }   
}

we didn't receive any complain about this service, but we prefer to be sure that no issue could be arise from that.

many thanks in advance for your help.