We noticed there are times when a site is running well and then someone at the hosting company decides it’s time to tighten security. When that happens on a site that has the server configured to parse html for php, it can result in a 403 forbidden error.
This error can also occur in several other causes such as when using cgi or other executable files.
This is because the html file the requires executable permission. If you’re having this problem and you are able to modify your .htaccess file, we recommend using a text editor to add this line at the end:
This will allow files to be executed in your root directory and all sub-directories. It seemed to fix the problem in the case we saw.
This problem may occur on any Apache server due the tightened security in the main httpd.conf file. Many times a hosting company may not expect html to be parsed for php, but parsing html for php is a very common practice.