Why does Trace.WriteLine("Test") not appear when targeting .net 4.0 but does when 3.5

Question

I have just noticed that when i call the following code from a console app

for (int i = 0; i < 10; i++)
{
  Trace.WriteLine("Logging");
  Debug.WriteLine("Logging Debug");
}

if I am targeting .net 4.0 no messages appear in the debugview app although I am capturing all outputs.

If I change to target 3.5 it appears fine.

What's changed and how can I fix it?

Answer 1

Are you doing this on the same machine?

It could be that the debug viewer (assumed DbgView from Sysinternals) is not connected. Check the title of the debug viewer for the name of the machine you're connected to.