TypeError: Error #1080: Illegal value for namespace. at Function/com.esri.ags.layers:WMSLayer/private:loadCapabilities/com.esri.ags.layers:myResultFunction()at mx.rpc::AsyncResponder/result()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/AsyncResponder.as:103] at mx.rpc::AsyncToken/http://www.adobe.com/2006/flex/mx/internal::applyResult()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/AsyncToken.as:247] at mx.rpc.events::ResultEvent/http://www.adobe.com/2006/flex/mx/internal::callTokenResponders()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/events/ResultEvent.as:215] at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::dispatchRpcEvent()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/AbstractInvoker.as:275] at HTTPOperation/http://www.adobe.com/2006/flex/mx/internal::dispatchRpcEvent()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/http/HTTPService.as:1006] at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::resultHandler()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/AbstractInvoker.as:326] at mx.rpc::Responder/result()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/Responder.as:64] at mx.rpc::AsyncRequest/acknowledge()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/rpc/AsyncRequest.as:92] at DirectHTTPMessageResponder/completeHandler()[/Users/justinmclean/Documents/ApacheFlex4.11.0/frameworks/projects/rpc/src/mx/messaging/channels/DirectHTTPChannel.as:459] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at flash.net::URLLoader/onComplete()
If someone has the same problem, i found a workaround.
The problem was, that with the authentification enabled, the flex API sends the request with POST. It seems that the WMS service can't handle that. So i implemented an HTTP Handler in .NET. In there i send the request with GET and not with POST. Set the proxyUrl property that it calls the HTTP handler and then it works.