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.
<IfModule !mpm_winnt_module>
<IfModule !mpm_netware_module>
  LockFile "/private/var/log/apache2/accept.lock"

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

  • This works. This happens when you update your MacOSX from your previous OSX version. – Placeholder Sep 27 '16 at 6:18

I looked up the information on the file http-mpm.conf at the Apache website:

It says LockFile is a correct directive. I don't know why I'm getting the same error you are. So in terminal, I went to:


and restored the httpd-mpm.conf file from before I loaded El Capitan. I used these commands:

sudo mv httpd-mpm.conf httpd-mpm.conf.elcapitan
sudo mv httpd-mpm.conf~orig httpd-mpm.conf

and entered the commands:

sudo apachectl restart
apachectl configtest

and got "Syntax OK"

If I enter http://localhost in my browser, I get the page "it works".

  • whats the important change from your original config file? I am starting from fresh so I don't have known working config file. – daslicious Oct 25 '15 at 23:31
  • I have the same issue, but this doesn't actually offer any fix. – Jake N Nov 24 '15 at 9:45

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protected by Community Dec 18 '15 at 22:04

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