Ecc queue returs HTTP status 0 if the payload exceeds maximum sizeIssue <!-- div.margin { padding: 10px 40px 40px 30px; } table.tocTable { border: 1px solid; border-color: #e0e0e0; background-color: #fff; } .title { color: #d1232b; font-weight: normal; font-size: 28px; } h1 { color: #d1232b; font-weight: normal; font-size: 21px; margin-bottom: 5px; border-bottom-width: 2px; border-bottom-style: solid; border-bottom-color: #cccccc; } h2 { color: #646464; font-weight: bold; font-size: 18px; } h3 { color: #000000; font-weight: bold; font-size: 16px; } h4 { color: #666666; font-weight: bold; font-size: 15px; } h5 { color: #000000; font-weight: bold; font-size: 13px; } h6 { color: #000000; font-weight: bold; font-size:14px; } ul, ol { margin-left: 0; list-style-position: outside; } --> When REST call is made through MID server you will see HTTP status returning as 0 and you can see below error in ECC queue. Payload size of 41047892 bytes exceeded maximum of 20000000 bytes. Contents of the original payload were moved to C:Dev Servermid.istanbul-09-23-2016__patch6-05-02-2017_05-19-2017_1034.windows.x86-64agentworkmonitorsECCSenderoutput_oversizeecc_queue.66daa695dbbea78064d87d8bbf961930.xml on the MID server. Maximum payload size can be set with mid config parameter: mid.eccq.max_payload_size ReleaseAllCauseThe limitation set in the system property mid.eccq.max_payload_size. Specifies the maximum string length of a payload that the MID server sends to the instance. The MID Server verifies the size of the payload before sending it to the instance, If the payload size exceeds the limit, the MID Server discards it and returns an error message in the payload.Resolution1) Go to MID Server > Properties. 2) Check if the property mid.eccq.max_payload_size does exist. 3) If the property exists, increase the size of the payload in bytes, if it doesn't exist create new and specify the payload size in bytes, default is 20000000 bytes. OR 1) you can also configure this as a configuration parameter on an individual MID Server 2) Please follow below documentation to configure the parameter on specific MID Server https://docs.servicenow.com/csh?topicname=mid-server-parameters.html&version=latest#t_SetMIDServerParameters