Writing a work-in-progress form in C# (WinForms)

https://codereview.stackexchange.com/q/226823/69346

Unexpected results with no exceptions being thrown - apparently

If you are facing undesired results or strange behaviors, but are not spotting any exception in run time - make sure you checked all the Common Language Runtime Exceptions in Debug -> Exception Settings.

I was facing an InvalidOperationException due to unsafe cross thread access.
But it was only when I instructed VS to break on all exceptions from the CLR, then I finally got the hint of where/who was raising the exception.