If you encounter an error message that…

1. Is not a PHP error
2. Does not have your site header
3. Is not an error message stating "This message was generated by b2evolution"

…then it is an error that happens BEFORE b2evolution is involved.

The most common causes are:

• You have a misconfigured .htaccess file that prevents b2evolution from executing
• You have a File Permission issue that prevents b2evolution from executing
• Your hosting provider as installed some "security" module (e-g: mod_security) that thinks it’s being smart by blocking some b2evolution request before it can execute

In order to find out you need to:

• Look at your server log files
• And/or ask your web host