# Troubleshooting System Debugger

There are two primary components to review when troubleshooting System Debugger problems:

> Debug hub

> Debug server

Ensure that the DEBUG HUB is active on your system. If it is not active, enter the command STRTCPSVR *DBG to start the server.

Ensure that the DEBUG SERVER (QTESPASSVR) job is active on your system. If it is not active and the DEBUG HUB (QTESDBGHUB) is active on your system, check the QTESPASSVR job log for additional information. All instances of the QTESPASSVR job are submitted to the QUSRNOMAX job queue, which feeds the QUSRWRK subsystem. To ensure that the debug server runs properly, make sure that the QUSRNOMAX job queue is not held and that the QUSRWRK subsystem is currently running.