Updated to 10.13.5, lost Bluetooth

I have unplugged all cables from my laptop (external video, power cable etc.) and shutdown it for 10 minutes. After starting it up again, bluetooth was available again.

Note that rebooting or shutting down for 1-2 minutes didn't help me.

Good luck!

Unplugging everything and turning my Mac off for 20 minutes worked. Shutdown, not restart. I can connect everything to Bluetooth again, and I can turn Bluetooth of and on now. Leave everything unplugged when you turn your Mac back on.

Boot into macOS recovery

https://support.apple.com/en-us/HT201314

If Bluetooth doesn't work there, then it's definitely a hardware issue with your Mac and you need to have it serviced

Same problem today to my MacBook Pro (Retina, 13-inch, Early 2015). Tried completely-shutting-down and both Bluetooth and lost device connections revived. One thing is that my trackpad has already been unpaired before the step but it just auto reconnected.

My 2015 MacBook Pro went into the Genius Bar today. They ran a hardware check, said I'd done everything they would of tried and said my only option now is to try a hardware replacement for the wifi/bluetooth card at £150.

Same problem ... deleting .plist didn't help. Just fixed it on my MBP with a full NVRAM reset - it got all my Bluetooth devices back.

Ok here's an update on my situation... Another phone call to Apple resulted in being told to either mail it to them, or take it to an Apple store, or another service provider. So there's a Simply Mac not too far away and I took it there. They confirmed it was NOT a hardware problem, but they did have to do a complete reformat and reinstall. I'm on 10.13.5 now and everything seems to be working fine.

I have this problem too, also reset the module, trashed the BT preferences and resetting SMC doesn't help.

The only fix is going back 10.13.4.

Nothing will work. It is a bug with the software update. Call Apple. It took us two days, but finally the issue went up to the Apple engineers who are working on a fix.

I zapped my NVRAM like others have mentioned, the OS went to default/stumbled twice on restart then fully restarted, BT and AirPlay came back to life, holding my breath.

Update to 10.13.6

I think that makes it pretty clear. Your Mac has a hardware issue and you should make an Apple store appointment.

the-real-jphnycat IT WORKS !

I Shutdown my mac after work, not restart, not sleep. I get back home and I turn it on after maybe 2 hours and it works 🙂 My Bluetooth is alive!

For me it worked to completely shut down my MacBook Pro. Not Restart, but completely shut down, wait a few minutes and switch it back on.

I had tried a few restarts, even removed all BT devices to try and reconnect them without success before.