The diagnostics tab is a feature that should only be used with the direction of a NinjaTrader technical support or your connectivity providers' customer support representative. This feature records low level tracing of the NinjaTrader application operations and events. Trace information is displayed in the window and written to files located in the <NinjaTrader Installation Folder>\trace folder. By default, this tab should be invisible. You can enable or disable visibility via the Tools-->Options menu, General Tab of the Control Center window.