Support » Pololu USB AVR Programmer User’s Guide » 5. Getting Started in Mac OS X »
5.a. Firmware Support for Mac OS X
If you want to use the programmer with Mac OS X 10.11 (El Capitan) or later, you will need to upgrade your firmware to version 1.08 or later by following the firmware upgrade instructions in Section 9. Firmware version 1.07 works with Mac OS X 10.7 through 10.10. However, there is a problem that causes the programmer’s virtual serial ports to frequently disappear and reappear when used on Mac OS X 10.11. This problem can be fixed by upgrading to firmware version 1.08 or later.