title: System.TypeInitializationException was unhandled HResult=-2146233036 ... at CurrentDomain_UnhandledException
body: <p>Presently, I am attempting to write error logs to a disk file using isolated storage.  Suddenly, I started receiving the following exception:</p>
  
  <pre><code>System.TypeInitializationException was unhandled
    HResult=-2146233036
    Message=The type initializer for 'MyAppUtilities.ErrorLogger' threw an exception.
    Source=MyAppUtilities
    TypeName=MyAppUtilities.ErrorLogger
    StackTrace:
         at MyAppUtilities.ErrorLogger.AuditMethodError(Exception exc, String threadName,    String service)
         at MyWatchdog.Program.CurrentDomain_UnhandledException(Object sender, UnhandledExceptionEventArgs e) in c:\DataService\MyWatchdog\Program.cs:line 20
    InnerException: System.ArgumentNullException
        HResult=-2147467261
        Message=Value cannot be null.
    Parameter name: path
        Source=mscorlib
        ParamName=path
        StackTrace:
          at System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, IsolatedStorageFile isf)
          at System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, IsolatedStorageFile isf)
          at System.IO.IsolatedStorage.IsolatedStorageFileStream..ctor(String path, FileMode mode, IsolatedStorageFile isf)
          at MyAppUtilities.ErrorLogger..cctor() in c:\DataService\DataServiceUtilities\ErrorLogger.cs:line 57
     InnerException:  
  </code></pre>
  
  <p>Here is basically the code I am using to write error messages:</p>
  
  <pre><code>    private static Assembly _assembly =
          System.Reflection.Assembly.GetExecutingAssembly();
      private static string _errorLogFile =
          _assembly.FullName + ".log";
      private static IsolatedStorageFile _isoStore =
          IsolatedStorageFile.GetStore(
          IsolatedStorageScope.User |
          IsolatedStorageScope.Assembly,
          null,
          null);
      private static IsolatedStorageFileStream _isoStream =
          new IsolatedStorageFileStream(_errorLogFile,
          FileMode.OpenOrCreate, _isoStore);
  
      public static void ApplicationAudit(string message)
      {
          using (StreamWriter sw = new StreamWriter(_isoStream))
          {
              _isoStream.Seek(0, SeekOrigin.End);
              sw.WriteLine("--------------------------------------------" +
                  "------------------------------");
              sw.WriteLine(DateTime.Now.ToString() + ": " + message);
          }
      }
  </code></pre>
  
  <p>Please note that, before I started using isolated storage, it worked fine when just writing to a file in the same directory as the executable.  I have spent some time searching the internet, but haven't found any posts with the same exception together with the inner exception as the one I am receiving.</p>
  
  <p>Does anyone have any ideas as to why I am receiving the above error?  TIA.</p>