Internal Error 500 Apache, but nothing in the logs?


I'm getting 500 Internal Server errors when I try to make an HTTP POST to a specific address in my app. I've looked into the server logs in the custom log directory specified in the virtual hosts file, but the error doesn't show up there so debugging this has been a pain in the ass.

How do I cause Apache to log Internal 500 errors into the error log?

12/11/2013 6:05:15 AM

Accepted Answer

Please Note: The original poster was not specifically asking about PHP. All the php centric answers make large assumptions not relevant to the actual question.

The default error log as opposed to the scripts error logs usually has the (more) specific error. often it will be permissions denied or even an interpreter that can't be found.

This means the fault almost always lies with your script. e.g you uploaded a perl script but didnt give it execute permissions? or perhaps it was corrupted in a linux environment if you write the script in windows and then upload it to the server without the line endings being converted you will get this error.

in perl if you forget

print "content-type: text/html\r\n\r\n";

you will get this error

There are many reasons for it. so please first check your error log and then provide some more information.

The default error log is often in /var/log/httpd/error_log or /var/log/apache2/error.log.

The reason you look at the default error logs (as indicated above) is because errors don't always get posted into the custom error log as defined in the virtual host.

Assumes linux and not necessarily perl

12/27/2019 12:50:19 AM

Check your php error log which might be a separate file from your apache error log.

Find it by going to phpinfo() and check for error_log attribute. If it is not set. Set it:

Maybe your post_max_size is too small for what you're trying to post, or one of the other max memory settings is too low.


I just ran into this and it was due to a mod_authnz_ldap misconfiguration in my .htaccess file. Absolutely nothing was being logged, but I kept getting a 500 error.

If you run into this particular issue, you can change the log level of mod_authnz_ldap like so:

LogLevel warn authnz_ldap_module:debug

That will use a log level of debug for mod_authnz_ldap but warn for everything else (


If your Internal Server Error information doesn't show up in log files, you probably need to restart the Apache service.

I've found that Apache 2.4 (at least on Windows platform) tends to stubbornly refuse to flush log files—instead, logged data remains in memory for quite a while. It's a good idea from the performance point of view but it can be confusing when developing.


The answers by @eric-leschinski is correct.

But there is another case if your Server API is FPM/FastCGI (Default on Centos 8 or you can check use phpinfo() function)

In this case:

  1. Run phpinfo() in a php file;
  2. Looking for Loaded Configuration File param to see where is config file for your PHP.
  3. Edit config file like @eric-leschinski 's answer.
  4. Check Server API param. If your server only use apache handle API -> restart apache. If your server use php-fpm you must restart php-fpm service

    systemctl restart php-fpm

    Check the log file in php-fpm log folder. eg /var/log/php-fpm/www-error.log


Add HttpProtocolOptions Unsafe to your apache config file and restart the apache server. It shows the error details.


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