C Sharp :: Getting Error When Word Add-in Run

I want to copy the word entered by a user as soon as the user presses space(Just like the spell checker in word editors do). I'm using the following code:

private void ThisAddIn_Startup(object sender, System.EventArgs e) {
        ConsoleKeyInfo info = Console.ReadKey();
        if (info.KeyChar == ' ') {
            Word.Range rng = this.Application.ActiveDocument.Words.Last;
          
[Code] .....

I'm getting the following error: An exception of type 'System.InvalidOperationException' occurred in mscorlib.dll but was not handled in user code. For the following line:

ConsoleKeyInfo info = Console.ReadKey();