Unknown SOAP Fault Error

We have build a new published web service in production environment in Mendix 4.7.2 : We are using a custom authentication in the header of this web service to make the sessioncurrent user is the public user accessing the web service . The client consuming this web service is complaining that he got sometimes two envelop tags in the same response as per the attached files and the second envelop has a soap fault string with value null which is not clear . The web service is used by many public users (by concurrent users). So,I would like to ask the following questions: 1- Why Mendix sometimes returns 2 soap envelopes for the same response 2- How can I identify what is null error reason 3- Is there any way to catch the soap fault error before responding to the client Kindly find the below response : <soap:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tns="http://www.emiratesid.ae/ws/eform/UserManagement"><soap:Body><tns:GetUserProfileResponse><UserDetails><fullName><![CDATA[SAIFUDDEEN OLIYANTAKATHU PAROL]]></fullName><username><![CDATA[saifudeen.op@gmail.com]]></username><mobileNumber><![CDATA[0559557418]]></mobileNumber><language><![CDATA[English]]></language><requiresSecurityQuestion>false</requiresSecurityQuestion></UserDetails></tns:GetUserProfileResponse></soap:Body></soap:Envelope><?xml version="1.0" encoding="utf-8"?><soap:Envelope   xmlns:xsd="http://www.w3.org/2001/XMLSchema"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><soap:Fault><faultcode>Server</faultcode><faultstring>null</faultstring></soap:Fault></soap:Body></soap:Envelope>
1 answers

There is actually only one envelop since it does not close. It is missing </soap:Envelope> just before the <soap:Body>

In this case the custom authentication in the header is the first suspect. Since it is only sometimes happening, the data is probably sometimes containing some strings that are processed wrong. And the emirates tend to use arabic characterset of some kind.