Help with an exception

[VBDT]

Hi guys, after two days of tiring to find a solution of a problem in my app I decide to ask for your help. The problem is when my application uninstalls it throws an exception (shown below). I think this has to do something with the application setting but of course I am not sure. I believe this started after I set some property of setup or application project but I don’t remember where it was. The property was about updating the application setting when a new version of app is installed. Anyways here is the exception message and the stack trace, if anyone knows anything about this, it can be helpful.
Thanks VBDT.

Error Message:
The parameter 'sectionGroupName' is invalid.
Parameter name: sectionGroupName

Source:
System.Configuration

StackTrace:
at System.Configuration.MgmtConfigurationRecord.GetSectionGroup(String configKey)
at System.Configuration.Configuration.GetSectionGroup(String sectionGroupName)
at System.Configuration.ClientSettingsStore.DeclareSection(Configuration config, String sectionName)
at System.Configuration.ClientSettingsStore.GetConfigSection(Configuration config, String sectionName, Boolean declare)
at System.Configuration.ClientSettingsStore.WriteSettings(String sectionName, Boolean isRoaming, IDictionary newSettings)
at System.Configuration.LocalFileSettingsProvider.SetPropertyValues(SettingsContext context, SettingsPropertyValueCollection values)
at System.Configuration.SettingsBase.SaveCore()
at System.Configuration.SettingsBase.Save()
at System.Configuration.ApplicationSettingsBase.Save()
at Screen_Shot.My.MySettings.AutoSaveSettings(Object sender, EventArgs e)
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnShutdown()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()

[VBDT]

I still can’t find the problem. Anyone has any suggestion?