JHTMLform not supported. Invalid Token

After you upgraded from Joomla! 1.5.0 to 1.5.2/1.5.3 you receive the error message JHTMLform not supported. Invalid Token. when trying to login to the backend. Or when trying to fill in a form or login on Front End you get Invalid Token or JHTMLform not supported. Invalid Token.

Follow the steps below in order to solve this problem

STEP 1

Locate the following path in your Joomla! installation in the root directory **/libraries/joomla/html/html/**and check if the file form.php is present.

STEP 2

If the file is missing create the file form.php in the **/libraries/joomla/html/html/**directory and add the code below in the form.php file.

CODE

STEP 3

Save the file and refresh your Joomla! page and the problem should now be solved.