Question

Tools|Options|Debugging Redirect all Output to Immediate is unchecked.
Tools|Options|Debugging|Output Window General output settings are all ON.
Debug configuration is activated, define DEBUG constant is checked.

Still Debug.WriteLine(“test”) writes nothing to Output Window(Cant capture it in DebugView from sysinternals too). What can cause that?

Answer 1

Had this in config file, hope that can help someone else:

<system.diagnostics>
    <trace>
      <listeners>
          <clear/>
      </listeners>
    </trace>
  </system.diagnostics>

removed clear, now everything works. Thank you @Hans Passant.