This is a long-standing and well known issue Mac Sierra users (don’t follow my suggested workaround in that thread—instead, follow what I’m suggesting below). This issue affects MacOS 10.11 and beyond.
If and when Singular Sound fixes the issue with a new release of the BeatBuddy Manager (BBM), the workaround is to use the BBM File - Export Project to SD card. The disadvantages are that depending on the size of your project, it will take a while for the process to complete and although as soon as it’s done, the Synchronize Project might again be active on the menu, as soon as you quit the BBM or restart your computer, the Synchronize Project will probably again be grayed out on the File menu. The other problem is that your pedal settings will be wiped out on your SD card. You can probably get around this by updating the settings on your pedal and then moving your SD card in your computer SD slot reader and copying the PARAMS folder from your card to your desktop. When you’ve completed the Export Project to SD card, you then copy the PARAMS folder back to the SD card. Some users report that it doesn’t work for them.
The other workaround is if you have utilities such as Carbon Copy Cloner or Super Duper. They can be set up to replicate the Synchronize Project to SD card. If you have those utilities on your Mac and would like to know how to set it up, reply to this thread.
You can search the forum for the answer to this and many other questions you might have.