Error on opening DbConnection.

[bicer]

hello everbody
i have wcf service that use linq to conncet Oracle but i get this error when i run

errorrrrrrrrrrrrrrrrrrrrrrrrr

Server stack trace:
at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
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 ConsoleApplication1.ServiceReference1.IDhmi_xslotq_heas12.Dhmi_X12DataAdd(Int32 value_a, Int32 value_b)
at ConsoleApplication1.ServiceReference1.Dhmi_xslotq_heas12Client.Dhmi_X12DataAdd(Int32 value_a, Int32 value_b) in c:\users\administrator\documents\visual studio 2010\Projects\ConsoleApplication1\ConsoleApplication1\Service References\ServiceReference1\Reference.cs:line 50
at ConsoleApplication1.Program.Main(String[] args) in c:\users\administrator\documents\visual studio 2010\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs:line 19
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()

[MariiaI]

Could you please specify the stack traces and full messages of all inner exceptions, as well as the connection string, which you are using.
Also, if possible, please send us the sample project with which this error could be reproduced.