Bluetooth serial failure has occurred

macOS Big Sur 11.1
latest Zwift launcher & app

Issue: if I have my UE Mega Boom 2 speakers (latest firmware) connected via BT to my Mac, when I launch Zwift, it automatically starts scanning BT devices and encounters “A Bluetooth serial failure”, as per the screenshot attached Screenshot 2020-12-29 at 23.01.31|264x280. Notably, it opens nonstop new windows claiming such a failure Screenshot 2020-12-30 at 10.15.12|690x424.

It seems to me that I cannot disable the BT scanning Zwift performs (I use the ANT+ channel for Zwift), which is something that would fix my problem, I guess.

I have the same problem but I am not on BT and I am on macbook pro. Did you manage to solve this problem at all? For me Zwift is becoming unusable and the intensity of this pop-ups seems to get worst each time I try to log in

Dear Laura,

I just gave up hope of being connected to my speakers when zwifting. If you are using the ANT+ signal to stream power and whatsoever just try disabling the BT on your mac before opening zwift and re-enable it afterward.


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Grazie mille. I’ll try this next time =)

Somewhere on Reddit ( r/Zwift/comments/k4g8s8/bluetooth_serial_failure/, actually), the suggestion was to unpair audio until after pairing bike gear.

That worked for me today!

I also switched to ANT+ and connected all my Wahoo gear (KICKR SNAP, TICKR, RPM) over ANT+ and then paired/connected my Powerbeats to my MacBook. Picked an Music playlist and then pounded out 45 mins on Zwift.


@Rob_C_Neo_2 - couple fixes here for the “Bluetooth Serial Failure” issues.

Hi, thanks for the feedback. I have done something similar. I disconnected one of the music devices from the mackbook’s bluetooth and now everything else works like magic.

Thanks for helping, all the Google Searches just returned a lot of technical talks and I couldn’t understand before this thread that the solution was this easy, heheh!

Thanks again,


I turned on my MBP, and started Zwift, and left it at the pairing screen and got busy and forgot about it.

I was horrified to come back to the screen and see probably 40 levels of Serial Error messages, and more popping up every second.

And nothing was paired. Nothing except for the keyboard and touchpad.

So it’s Zwift?

I was so sure it started with the Kickr Bike, and it, apparently completely coincidentally, did.

So disappointed…

And Sorry Wahoo! I was wrong…

I have the same issue when my Aftershokz is connected. It works fine with my bluetooth mouse and keyboard. (I’m on a Macbook pro)