El Capitan Apache error message AH00526 Yesterday I upgraded my Mac from Mountain Lion to El Capitan. Trying to get apache2 working I get the following error message: 


  AH00526: Syntax error on line 20 of /private/etc/apache2/extra/httpd-mpm.conf: Invalid command 'LockFile', perhaps misspelled or defined by a module not included in the server configuration.


What might be the remedy?
LockFile is one of the directives of Apache ≤ 2.2. This was replaced by Mutex in Apache 2.4, which is the version of Apache installed with OS X 10.11, El Capitan.

Edit the file /etc/apache2/extra/httpd-mpm.conf to remove this part:

#
# The accept serialization lock file MUST BE STORED ON A LOCAL DISK.
#
&lt;IfModule !mpm_winnt_module&gt;
&lt;IfModule !mpm_netware_module&gt;
  LockFile "/private/var/log/apache2/accept.lock"
&lt;/IfModule&gt;
&lt;/IfModule&gt;


Then check config apachectl -t and restart sudo apachectl restart.