"The given key was not present in the dictionary" error

HI there,

I would like your help please. I’ve reported this issue at codeplex but I’ve realised I should have raised it here. Apologises.

I’ve created an IVR script on a webserver. It keeps failing randomly. To find out the issue, I wrote a CurrentDomain_UnhandledException. It prints out a message and the source of the error.

It gave this error.

The given key was not present in the dictionary. 

System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
   at AsterNET.FastAGI.AGIConnectionHandler.Run() in e:\Projects\Codeplex\AsterNET\Asterisk.2013\Asterisk.NET\FastAGI\AGIConnectionHandler.cs:line 103
   at AsterNET.Util.ThreadTask.Run() in e:\Projects\Codeplex\AsterNET\Asterisk.2013\Asterisk.NET\Util\ThreadTask.cs:line 36
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

This is how I configured the agiServer component before starting it.

int PortNumber = ToolboxHelper.getSettingByNameAsInt("PortNumber");

            AsteriskFastAGI agiServer=new AsteriskFastAGI
            {
                MappingStrategy = new GeneralMappingStrategy(
                    new List<ScriptMapping>()
                    {
                        new ScriptMapping()
                        {
                            ScriptName = "callmonitor", // script name - passed by the Asterisk server
                            ScriptClass = "AsteriskAGI.CallMonitorAGI" // code to run for this script
                        }
                    })
            };

            agiServer.BindPort = PortNumber;

           try
            {
                agiServer.Start(); // Start the service. This runs synchronously - ctrl+c to exit

            }
            catch (Exception ex)
            {

            }

This error is occuring in the AsterNET code.

What’s happening in AGIConnectionHandler.cs at line 103? What key is it expecting? This happens randomly, perhaps also when a call has connected with my script.

Am I missing something in my setup?

[jjowens]

I’ve downloaded the source and made some changes to find the root of the issue. Apologises for the long post.

In AGIConnectionHandler.cs, around lines 93, where it throws an exception. I commented out the “throw ex” and got it to write the error message.

catch (AGIException ex)
            {
#if LOGGER
                logger.Error("AGIException while handling request", ex);
#else
                //throw ex;
                              writeToLog("AGiConnectionError: AGIException:" + ex.ToString());
#endif
            }

I found where the error was occuring.

AGiConnectionError: Ex:System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at AsterNET.FastAGI.AGIRequest.get_Script() in SNIP[..]\Asterisk.2013\Asterisk.NET\FastAGI\AGIRequest.cs:line 343
   at AsterNET.FastAGI.MappingStrategies.GeneralMappingStrategy.DetermineScript(AGIRequest request) in SNIP[..]Asterisk.2013\Asterisk.NET\FastAGI\MappingStrategies\GeneralMappingStrategy.cs:line 132
   at AsterNET.FastAGI.AGIConnectionHandler.Run() in SNIP[..]Asterisk.2013\Asterisk.NET\FastAGI\AGIConnectionHandler.cs:line 64

I looked inside AGIRequest.cs for line 343, GeneralMappingStrategy.cs for line 132 and AGIConnectionHandler.cs for line 64.

AGIRequest.cs

#region Script()
        /// <summary>
        /// Returns the name of the script to execute.
        /// </summary>
        public string Script
        {
            get
            {
                if (script != null)
                    return script;

                script = ((string)request["network_script"]); // <--- THIS IS LINE 343
                if (script != null)
                {
                    Match scriptMatcher = Common.AGI_SCRIPT_PATTERN.Match(script);
                    if (scriptMatcher.Success)
                    {
                        script = scriptMatcher.Groups[1].Value;
                        parameters = scriptMatcher.Groups[2].Value;
                    }
                }
                return script;
            }
        }
        #endregion

GeneralMappingStrategy.cs

        public AGIScript DetermineScript(AGIRequest request)
        {
            AGIScript script = null;
            if (mapAssemblies != null)
                lock (mapAssemblies)
                {
                    if (mapAssemblies.ContainsKey(request.Script))
                        script = mapAssemblies[request.Script].CreateInstance(); // THIS IS LINE 132
                }
            return script;
        }

AGIConnectioHandler.cs

AGIReader reader = new AGIReader(socket);
                AGIWriter writer = new AGIWriter(socket);
                AGIRequest request = reader.ReadRequest();
                AGIChannel channel = new AGIChannel(writer, reader, this._SC511_CAUSES_EXCEPTION, this._SCHANGUP_CAUSES_EXCEPTION);
                AGIScript script = mappingStrategy.DetermineScript(request); // THIS IS LINE 64
                Thread.SetData(AGIConnectionHandler.channel, channel);

So what happened, it was trying to find the script from the Dictionary (mapAssemblies) with the “network_script” variable/name so an instance of the script can be created and executed.

What is “network_script”? Is this something I need to declare in my AGIServer setup?

I looked at examples in https://asternetsamples.codeplex.com/ and I don’t see anything referring to “network_script”, except I didn’t use the Answer(); or HangUp(); in my script. Are they required? I was able to execute the script without those. The random hanging still occurs. Example

 public override void Service(AGIRequest param1, AGIChannel param2)
        {       
            Answer(); // Answer the call
// snip
            HangUp(); // End the call
        }

[jjowens]

Hi skrusty,

It’s written as a console application and it’s installed on a server. It’s a console applicaiton with framework set to 4.5.

This happens randomly. Is there any more infornation you would like?