Q: wireless Apple keyboard stalls requires restart

I have exactly this same problem. Seems to only happen sometimes after iMac (2015 5K) has been asleep.. comes back and I can enter password OK and everything looks normal until you start typing. Never had a problem with Yosemite - only El Capitan.

I then experience

• excessive keyboard lag where keypresses dont appear for ages, if at all
• lots of 'binging' - as if you've just held lots of keys down

ALready been onto apple support once - not much use

I tried killing off all apps and extensions - no change. Disconnecting the keyboard via bluetooth doesnt help either.

Only a reboot fixes it. I am running AVG anti-virus so I'll try to disable  that and see if it makes a difference

Same here. Bluetooth keyboard not working correctly, big delay and  sound after sleep on Mac Mini late 2012. This EL Capitan release if really buggy. Evrythnig worked ok in Yosemite.

Just been on to apple support again, this time they said

1. Turn off and remove power cord to 15 secs to reset SMC
2. Boot in recovery and run a disk check (was all OK)
3. Boot back into full OS, remove and re-add the system admin keyboard

Have done all the above and so now hoping the problem is resolved.. fingers x'd

Sadly not.

Keyboard went flakey the very next time it came out of sleep. Interesting that it was after only 30 mins - so the Mac hadn't suspended RAM to disk as than only happens after 3-4hrs.

Having the same issue here.  Upon wake from sleep keyboard is unresponsive, lags in registering key presses and sometimes type multiples of the same keypress.  Only happens with wireless keyboard.  Built-in keyboard on my Macbook Pro works fine.  Really hoping they fix this in 10.11.1.

Bluetooth devices become unresponsive

Bluetooth Interference Sources

Bluetooth Interference Sources (2)

If your Wi-Fi is capable of generating a 5 GHz signal, try that.

Sadly not my problem... no problem paring BT devices and neither mouse or trackpad affected. Problem also only occurred after upgrading El Capitan.

FIXED!!

After creating a clean admin account for test purposes and booting in safe mode, in which both still experienced keyboard lock-ups.. apple suggested a clean OS install.

Stuff that! I didnt want to spend all day having to re-install all my apps etc. So on the off chance it might work I did a re-install (over-install) from Recovery mode and it worked.

No loss of docs or apps... but keyboard has now been OK for over 24hrs with multiple short and long sleeps.

Thanks for the advice. I gave it a try and am still testing it out. Will report back results. One positive thing I noticed right away is that my keyboard is once again reporting battery status on the bluetooth preferences pane. After my initial upgrade to El Capitan, I had noticed that the battery status was missing in this window (although it still appeared under the Bluetooth icon in the menu bar).

Unfortunately the issue returned for me when using the external keyboard this morning after being asleep overnight. Going to wait for 10.11.1 to see if that fixes this. Only started after I updated to El Capitan, so I'm thinking it a bug in OS.

So, upgrading to 10.11.1 did not fix my issue with a lagging wireless Apple keyboard. Upon first wake from sleep the keyboard exhibited the same symptoms.

I've been searching this and other forums for insights since my problem started. I found an interesting thread on these forums that may have helped. The poster was having troubles with a Magic Mouse stuttering and losing connection. He finally solved his issue by moving (not copying) the plist files for Bluetooth onto his desktop and restarting his Mac. The plists were recreated upon restart by OS X and his problem was solved. Seems the Bluetooth connections profile had been corrupted and the fresh ones created by OS X restored the use of his mouse. I gave it a try and so far my keyboard has been working normally when coming out of sleep. My Apple keyboard, mouse and trackpad were automatically reconnected at startup, but other Bluetooth devices have to be re-paired.

If you want to try it for yourself here are the steps the other poster outlined:

"Move the following files to the Desktop and restart:

• /Library/Preferences/com.apple.Bluetooth.plist*
• ~/Library/Preferences/com.apple.Bluetooth.plist*
• ~/Library/Preferences/ByHost/com.apple.Bluetooth.*

It’s important to move (not copy) the files. This forces OS X to re-create the files on reboot. (I could have just deleted the files but I wanted to keep them around as backups in case something went wrong.) Since doing this, my Bluetooth devices have been happily connecting and disconnecting appropriately and I have no more stuck devices in my Preferences"

Thanks to Matthew Bass for the above suggestion. I have placed my MacBook Pro into sleep mode several times and the keyboard continues to work as it should. Previously the keyboard lag would always be present when I woke the computer from an overnight sleep. This morning my keyboard was working normally. I am hopeful that the issue has been resolved, but will report back to let you all know how it goes over the next couple of days.  I was just about to take the plunge and do a clean install of El Capitan (which probably would have solved the issue also) but hopefully won't need to go through the hassle now!

I am at work and don't have access to my MacBook right now but I will do the best I can to help you.

I am thinking you were able to find the first file listed (/Library/Preferences/com.apple.Bluetooth.plist).  The reason you can't find the other (~Library) folder is because it is normally hidden by OS X.  Click link below for instructions on how to access this folder from Apple Support.

OS X El Capitan: Library folder

To move files rather than copy you can either:

1.  Hold the CMD (command) button while you drag the file to your desktop; or

2. Use Cut and Paste keyboard shortcuts (CMD-X for cut and CMD-V) for paste.

Note: I only found two of the plist files on the list on my Mac (the first and the last ones), so don't be two concerned if the same happens to you.

Let me know how you make out.  If you're stilling having problems I can give you more detailed help when i get home tonight.