corrected wrongly negated if-statement, fixes #1337

CHANGELOG.md

@@ -3,6 +3,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Added
+### Changed
+### Fixed
+- #1337: Unhandled exception after closing mRemoteNG
+
 ## [1.77.1] - 2019-09-02
 ### Added
 - #1512: Added option to close panel from right click menu

mRemoteV1/Tools/Tools.SystemMenu.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Drawing;
 using mRemoteNG.App;
 using Microsoft.Win32.SafeHandles;
@@ -86,7 +86,7 @@ namespace mRemoteNG.Tools
         protected override void Dispose(bool disposing)
         {
             if (disposed) return;
-            if (!disposing) return;
+            if (disposing) return;
 
             ReleaseHandle();