From the menu, select View > Show Line Numbers.
or
Right-click in the left margin and select Show Line Numbers from the pop-up menu.
Query Microchip Forums and get your questions answered by our community:
Microchip Forums AVR Freaks Forums
If you need to work with Microchip Support staff directly, you can submit a technical support case. Keep in mind that many questions can be answered through our self-help resources, so this may not be your speediest option.
Technical Support Portal