after a while of sleep when i wake my mac , i can't use my keyboard to log in
this occurs on my 5k imac but i have a friend and even on a macbook happen
i thing they need to fix this
No I have not done a clean install of 10.11.1 based on advice in the Apple discussions forum in which someone else with the same issue did a reinstall of the OS and it did not fix the issue. To temporarily relieve the issue you can go to the energy settings pane and check "prevent this computer from sleeping when screen turns off". I have also read that instead of restarting your MacBook, turning the keyboard off and back on will also temporarily relieve the issue.