Object synchronization method was called from an u

Question

I have found different articles about this exception but none of them was my case. Here is the source code:

class Program
{

    private static Mutex mutex;
    private static bool mutexIsLocked = false;
    static void Main(string[] args)
    {

        ICrmService crmService = 
            new ArmenianSoftware.Crm.Common.CrmServiceWrapper(GetCrmService("Armsoft", "crmserver"));
        //Lock mutex for concurrent access to workflow
        mutex = new Mutex(true, "ArmenianSoftware.Crm.Common.FilterCtiCallLogActivity");
        mutexIsLocked = true;

        //Create object for updating filtered cti call log
        ArmenianSoftware.Crm.Common.FilterCtiCallLog filterCtiCallLog =
            new ArmenianSoftware.Crm.Common.FilterCtiCallLog(crmService);
        //Bind events
        filterCtiCallLog.CtiCallsRetrieved += new EventHandler<ArmenianSoftware.Crm.Common.CtiCallsRetrievedEventArgs>(filterCtiCallLog_CtiCallsRetrieved);

        //Execute filter
        try
        {
            filterCtiCallLog.CreateFilteredCtiCallLogSync();
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            if (mutexIsLocked)
            {
                mutexIsLocked = false;
                mutex.ReleaseMutex();
            }
        }
    }

    static void filterCtiCallLog_CtiCallsRetrieved(object sender,
         ArmenianSoftware.Crm.Common.CtiCallsRetrievedEventArgs e)
    {
        tryasasas
        {
            if (mutexIsLocked)
            {
                mutexIsLocked = false;
                mutex.ReleaseMutex();
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
}

filterCtiCallLog.CreateFilteredCtiCallLogSync(); function executes requests to server, and raises some events, one of which is CtiCallsRetrieve event. And I need to release the mutex when this event is fired. But on calling the mutex.Release() function exception is thrown. CreateFilteredCtiCallLogSync works synchronously. What is the problem?

Answer 1

Maybe not the most meaningful error message, I've seen this happen in some third party code as below,

object obj = new object();
lock (obj)
{
    //do something

    Monitor.Exit(obj);//obj released

}//exception happens here, when trying to release obj