It’s a known issue http://forum.mybeatbuddy.com/index.php?threads/mac-sierra-users.7490/
The disadvantage to the workaround is losing your pedal settings however, before trying the export workaround you could try
- making sure your SD card has your latest pedal settings; insert your SD card in your computer SD slot reader;
- copy the PARAMS folder from your SD card to your desktop and once you complete the export process, copy the PARAMS folder from your desktop to your SD card
It may or may not work for you but it might be worth a try. Small print disclaimer: this is probably one of the few exceptions you should use the OS to perform a function reserved for the BBM. Worst that could happen is you may have to manually reset your pedal settings.