Settings - first chance exception of type 'System.NullReferenceException'

EDN Admin · Jun 15, 2006

Im getting following exception : 
A first chance exception of type System.NullReferenceException occurred in Copy DB.exe
When using the following code (bold part) : 
private void cboDatabase_SelectedIndexChanged(object sender, EventArgs e)
{
string s = ((ComboBox)sender).Text.Substring(((ComboBox)sender).Text.IndexOf("_") + 1);
int i;
if (int.TryParse(s.Substring(s.IndexOf("_") + 1, 1), out i))
{
s = s.Substring(0, s.IndexOf("_"));
}
else
{
s = s.Substring(0, s.IndexOf("_", s.IndexOf("_") + 1));
}
if (UserSettings.Default != null)
try
{
tbTargetDatabaseName.Text = UserSettings .Default.PropertyValues[_s_].PropertyValue.ToString();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
tbTargetDatabaseName.Text = UserSettings.Default.Properties[_s_].DefaultValue.ToString();
}
else
tbTargetDatabaseName.Text = s;
SelectScripts(((ComboBox)sender).Text, ref clbScripts);
}
This event is firing when I select another item in my combobox, each time I end up with the Excepion in my console window... Unless I set a breakpoint on the line (which causes the exception) and add " .Default.PropertyValues[_s_].PropertyValue" to the watch. Afterwards I can remove the breakpoint and trigger the event (time after time) without any issue.
Anyone knows whats the reason for this behaviour ?
ps, I used [_s_] as it became a moon-emoticon when using only s. 

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Settings - first chance exception of type 'System.NullReferenceException'

EDN Admin

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