diff --git a/ADP/ViewModels/ShellViewModel.cs b/ADP/ViewModels/ShellViewModel.cs
index f7e6103..dd710bb 100644
--- a/ADP/ViewModels/ShellViewModel.cs
+++ b/ADP/ViewModels/ShellViewModel.cs
@@ -208,7 +208,7 @@ namespace ADP.ViewModels
             SilenceBuzzerCommand = new AsyncDelegateCommand(SilenceBuzzer);
             GoBackCommand = new DelegateCommand(OnGoBack);
 
-            _globalInfo.ContextDic.Add("default", new ScopedContext());
+            _globalInfo.ContextDic.TryAdd("default", new ScopedContext());
 
             _eventAggregator.GetEvent<LoginSuccessEvent>().Subscribe(() =>
             {
diff --git a/MainModule/ViewModels/AutomatedTestingViewModel.cs b/MainModule/ViewModels/AutomatedTestingViewModel.cs
index 0b586a0..9abf25e 100644
--- a/MainModule/ViewModels/AutomatedTestingViewModel.cs
+++ b/MainModule/ViewModels/AutomatedTestingViewModel.cs
@@ -217,10 +217,10 @@ namespace MainModule.ViewModels
                 (LogAreaVM as IDisposable)?.Dispose();
                 (ParametersManagerVM as IDisposable)?.Dispose();
 
-                _globalInfo.ContextDic?.Remove(TestStatus);
-                _globalInfo.StepRunningDic?.Remove(TestStatus);
-                _globalInfo.ConfigDic?.Remove(TestStatus);
-                _globalInfo.ScopeDic?.Remove(TestStatus); 
+                _globalInfo.ContextDic?.TryRemove(TestStatus, out _);
+                _globalInfo.StepRunningDic?.TryRemove(TestStatus, out _);
+                _globalInfo.ConfigDic?.TryRemove(TestStatus, out _);
+                _globalInfo.ScopeDic?.TryRemove(TestStatus, out _); 
             }
             catch (Exception ex)
             {
@@ -275,10 +275,10 @@ namespace MainModule.ViewModels
             if (navigationContext.Parameters.ContainsKey("Name"))
             {
                 TestStatus = navigationContext.Parameters.GetValue<string>("Name");
-                _globalInfo.ContextDic.Add(TestStatus, _scopedContext);
-                _globalInfo.StepRunningDic.Add(TestStatus, _stepRunning);
-                _globalInfo.ScopeDic.Add(TestStatus, _scope);
-                _globalInfo.ConfigDic.Add(TestStatus, _systemConfig);
+                _globalInfo.ContextDic.TryAdd(TestStatus, _scopedContext);
+                _globalInfo.StepRunningDic.TryAdd(TestStatus, _stepRunning);
+                _globalInfo.ScopeDic.TryAdd(TestStatus, _scope);
+                _globalInfo.ConfigDic.TryAdd(TestStatus, _systemConfig);
                 if(_systemConfig.DefaultProgramFilePath != null&&File.Exists(_systemConfig.DefaultProgramFilePath))
                 {
                     var filePath = _systemConfig.DefaultProgramFilePath;