404 Error when to accessing /wp-admin/admin-ajax.php

When you receive this error:ForbiddenYou don’t have permission to access /wp-admin/admin-ajax.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

If you are receiving this error, then its likely you have mod_security installed on your server, and you will need to update your mod_security rules.

Find the following in your mod_security configuration:

Only accept request encodings we know how to handle
# we exclude GET requests from this because some(automated)
# clients supply "text/html" as Content-Type
SecFilterSelective REQUEST_METHOD "!^(GET|HEAD)$" chain
SecFilterSelective HTTP_Content-Type "!(^application/x-www-form-urlencoded$|^multipart/form-data;|^text/xml;)"

Change it to:

# Only accept request encodings we know how to handle
# we exclude GET requests from this because some (automated)
# clients supply “text/html” as Content-Type
SecFilterSelective REQUEST_METHOD “!^(GET|HEAD)$” chain
SecFilterSelective HTTP_Content-Type “!(^application/x-www-form-urlencoded;|^multipart/form-data;|^text/xml;)”

If you don’t have access to mod_security configuration (i.e. you are not the administrator of the server), then you can add the following to a .htaccess file for your site:

<IfModule mod_security.c>
SecFilterInheritance Off
</IfModule>

Filed under: Uncategorized by — aaron @ 4:56 pm

Server hung at ‘Probing PCI hardware bus (00)’

Error: Probing PCI hardware bus (00), server hung at this message, while booting.

The problem can be fixed by adding the kernel flag ‘pci=nommconf’ in the kernel command line in the grub.

1) Reboot the server.

2) At the grub boot screen, select the kernel and press ‘e’ to edit the entry.

3) Select the kernel command line and press ‘e’ to edit the entry, which looks like

kernel /vmlinuz-x.x.x-x.x ro root=/dev/abc/ acpi=off

4) Add pci=nommconf at the end of the line, like

kernel /vmlinuz-x.x.x-x.x ro root=/dev/abc/ acpi=off pci=nommconf

5) Then press enter and press ‘b’ to boot.

Once the server reboots and comes online, edit the grub.conf and add ‘pci=nommconf’ in the default kernel’s kernel command line. (kernel /vmlinuz-x.x.x-x.x ro root=/dev/abc/ acpi=off pci=nommconf)

Filed under: Uncategorized by — aaron @ 2:53 pm