Error 403 on form submit

Question

I\'ve got a problem with a form in the administration area of my website. I use it for changing the displayed HTML text, it is written in PHP and connects to a MySQL databas

Answer 1

Just adding to this to say that I also had this problem and it turned out to be a mod_security rule that false-positived, that caused the problem. The host of the site was able to whitelist the domain against the particular rule. The rule was apparently 211580 - "COMODO WAF: SQL Injection Attack".