When does this error appear on the display? Is it reproducible every time? Do you have MIDI cables connected to the QS7 when it happens?
Since the QS7 is a legacy product, I recommend checking online with third-party forums and websites for further assistance. You may also get in touch with our Technical Support team for assistance. Please keep in mind, support for legacy products is limited, as we mainly support our current in-line products. You can get in touch with Technical Support by logging on to www.alesis.com/support. Select Technical Support from the drop-down menu.