Can not start JACK

Wed Mar  1 12:50:58 2017: Starting jack server...
Wed Mar  1 12:50:58 2017: JACK server starting in realtime mode with priority 10
Wed Mar  1 12:50:58 2017: self-connect-mode is "Don't restrict self connect requests"
Wed Mar  1 12:50:58 2017: ERROR: Cannot lock down 82274202 byte memory area (Cannot allocate memory)
Wed Mar  1 12:50:58 2017: ERROR: cannot register object path "/org/freedesktop/ReserveDevice1/Audio0": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Wed Mar  1 12:50:58 2017: ERROR: Failed to acquire device name : Audio0 error : A handler is already registered for /org/freedesktop/ReserveDevice1/Audio0
Wed Mar  1 12:50:58 2017: ERROR: Audio device hw:0 cannot be acquired...
Wed Mar  1 12:50:58 2017: ERROR: Cannot initialize driver
Wed Mar  1 12:50:58 2017: ERROR: JackServer::Open failed with -1
Wed Mar  1 12:50:58 2017: ERROR: Failed to open server
Wed Mar  1 12:51:00 2017: Saving settings to "/home/admin/.config/jack/conf.xml" ...
12:51:01.740 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started

What to do?

[sonicpp]

Are you sure it is jack1, not jack2?

This might help, if your system has enough memory:
https://askubuntu.com/a/166140/920830