ProtocolException was unhandled by user code

[AhmedEasaHadaf]

I am getting this exception while returning any result from the api
Exception Message
The content type text/html; charset=UTF-8 of the response message does not match the content type of the binding (text/xml; charset=utf-8). If using a custom encoder, be sure that the IsContentTypeSupported method is implemented properly. The first 1024 bytes of the response were: '

Deprecated: Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini and use the php://input stream instead. in Unknown on line 0



Warning: Cannot modify header information - headers already sent in Unknown on line 0



Warning: session_start(): Cannot send session cookie - headers already sent in C:\wamp64\www\Mantis-new\core\session_api.php on line 121



Warning: session_start(): Cannot send session cache limiter - headers already sent in C:\wamp64\www\Mantis-new\core\session_api.php on line 121

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://futureware.biz/mantisconnect" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml'.

StackTrace:

Server stack trace:
at System.ServiceModel.Channels.HttpChannelUtilities.ValidateRequestReplyResponse(HttpWebRequest request, HttpWebResponse response, HttpChannelFactory1 factory, WebException responseException, ChannelBinding channelBinding) at System.ServiceModel.Channels.HttpChannelFactory1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at Futureware.MantisConnect.MantisConnectWebservice.MantisConnectPortType.mc_config_get_string(String username, String password, String config_var)
at Futureware.MantisConnect.MantisConnectWebservice.MantisConnectPortTypeClient.mc_config_get_string(String username, String password, String config_var) in G:\Hadaf work\HadafSupportSystem\MantisConnect\Service References\MantisConnectWebservice\Reference.cs:line 3707
at Futureware.MantisConnect.Request.ConfigGet(String config, String& str) in G:\Hadaf work\HadafSupportSystem\MantisConnect\Request.cs:line 544
at Futureware.MantisConnect.Config.Get(String config, String& str) in G:\Hadaf work\HadafSupportSystem\MantisConnect\Config.cs:line 147
at Futureware.MantisConnect.Config.Get(String enumerationName, MantisEnum& enumeration) in G:\Hadaf work\HadafSupportSystem\MantisConnect\Config.cs:line 165
at Futureware.MantisConnect.Config.Get(String enumerationName) in G:\Hadaf work\HadafSupportSystem\MantisConnect\Config.cs:line 181
at Futureware.MantisConnect.Config.get_ReproducibilityEnum() in G:\Hadaf work\HadafSupportSystem\MantisConnect\Config.cs:line 93
at HadafCompanySystem.Repository.MantisRepository.b__8_0() in G:\Hadaf work\HadafSupportSystem\HadafCompanySystem\Repository\Mantis\MantisRepository.cs:line 84
at System.Threading.Tasks.Task`1.InnerInvoke()
at System.Threading.Tasks.Task.Execute()