Error when calling an external web service (blank soap action)

Question

I did a lot of searching on this message and did not find an answer. Most of the issues i found related to XI/PI, which we are not using.
There is a web service created outside of SAP for which i generated (from the WSDL) a proxy class in my DEV system, client 050, a few years ago. This was subsequently moved to QA and production, and all is working fine.
Now, i want the same web service to work in client 100. I created the logical port, and the RFC destination, but when i try to call the web service, i get the following error
Server did not recognize the value of HTTP Header SOAPAction
Since only the basis group around here can access the logical port definition,and rfc destination, i have no idea where this information should be set up. I should not have to reimport the WSDL, since the proxy was imported from DEV to QA and it is working in QA client 050. There is something i need to set up, specific to client 100, and i am missing it. I looked in SOAMANAGER, and i didnt see anything even set up  there for client 050, so i did set up anything for client 100.
Any help would be appreciated.

Answer 1

I tried adding the web reference in a console app and works fine. In the plugins this can't be done, because the plugins are deploy in database.
I tried another basic test using ChannelFactory. Only want to retrieve some entity through the external web services:
IPluginExecutionContext context = localContext.PluginExecutionContext;
IOrganizationService service = localContext.OrganizationService;
ITracingService tracer = localContext.TracingService;
try
BasicHttpBinding binding = new BasicHttpBinding();
binding.Name = "BasicHttpBinding_IAxxisWcfServices";
binding.Security.Mode = BasicHttpSecurityMode.None;
binding.Security.Transport.ProxyCredentialType = HttpProxyCredentialType.None;
binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.None;
EndpointAddress endpoint = new EndpointAddress(@"http://*****.svc");
ChannelFactory<IAxxisWcfServices> factory = new ChannelFactory<IAxxisWcfServices>(binding, endpoint);
IAxxisWcfServices channel = factory.CreateChannel();
var entity = channel.FindByEntities(new CRM.Application.Context.Dtos.Asegurado( { CrmGuid = "7C3E96C6-C3BC-E411-80DF-0A736AE14667" }, null, new CRM.Framework.Session() { User = "***", Password = "***" });
catch (Exception ex)
throw new InvalidPluginExecutionException(ex.Message);
That test threw the following exception on the GenericParameterAttributes of channelType of factory object:
http://s27.postimg.org/4wf3er8up/Error.png