Error after updating Apache on Ubuntu 13.04 (Raring Ringtail)

Question

I have an error after updating my packages. When trying to start my webserver, it throws the following error.

$ sudo service apache2 restart
 * Restarting web server apache2    [fail]
 * The apache2 configtest failed.
Output of config test was:
AH00526: Syntax error on line 84 of /etc/apache2/apache2.conf:
Invalid command 'LockFile', perhaps misspelled or defined by a module not included in the server configuration
Action 'configtest' failed.
The Apache error log may have more information.

And the Apache error log is (from file /var/log/apache2/error.log):

[Sat Aug 17 01:30:03 2013] [notice] Apache/2.2.22 (Ubuntu) PHP/5.4.17RC1 configured -- resuming normal operations
[Sat Aug 17 01:41:38 2013] [notice] caught SIGTERM, shutting down
[Sat Aug 17 03:10:11.132425 2013] [mpm_prefork:notice] [pid 4182] AH00163: Apache/2.4.6 (Ubuntu) PHP/5.5.1-2+debphp.org~raring+2 configured -- resuming normal operations
[Sat Aug 17 03:10:11.143718 2013] [core:notice] [pid 4182] AH00094: Command line: '/usr/sbin/apache2'
[Sat Aug 17 03:13:56.527245 2013] [mpm_prefork:notice] [pid 4182] AH00169: caught SIGTERM, shutting down

What things do I have to do to recover or fix my server up?

Answer 1

Replace in apache2.conf:

LockFile /var/lock/apache2/accept.lock

with

Mutex file:${APACHE_LOCK_DIR} default