ProtocolException Received when Calling WCF service - asp.net

Question

I am having this problem since a week now and am unable to resolve this. I have looked at various posts but found nothing related to the problem.
I have a website and a WCF service inside the same website project. It was all working fine, but suddenly, the WCF service client is not able to receive a valid response from the service.
Error message:
ProtocolException occured
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: '
Value cannot be null.Parameter name: input
body {font-family:"Verdana";font-weight:norma....
I don't understand what is this parameter input. How can I resolve this issue? The WCF service is accessible via browser using the endpoint mentioned in the web.config
Here is the code:
Code behind:
using (var client = new Agent4HomeWebsite.PhotosWebServiceRef.PhotosWebServiceClient())
{
var temp = client.GetImageObjects();
}
Web.config:
<configuration>
....
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpBinding_IPhotosWebService" />
</basicHttpBinding>
</bindings>
<client>
<endpoint
address="http://localhost:49274/PhotosWebService.svc"
binding="basicHttpBinding"
bindingConfiguration="BasicHttpBinding_IPhotosWebService"
contract="PhotosWebServiceRef.IPhotosWebService"
name="BasicHttpBinding_IPhotosWebService" />
</client>
<behaviors>
<serviceBehaviors>
<behavior name="">
<serviceMetadata httpGetEnabled="true" />
<serviceDebug includeExceptionDetailInFaults="false" />
</behavior>
</serviceBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
</system.serviceModel>
</configuration>