Hi everyone. My site had been suffering from this issue for several months until yesterday. I wasn’t able to update my pages and add widgets to my footer and header. I could not find a solution anywhere on the internet, so I felt I have to post the solution I found.
This issue was related to the ModSecurity tool.
ModSecurity is an Apache module that works as a web application firewall. It blocks known exploits and protects from a range of attacks against web applications. However, sometimes, mod_security may incorrectly determine that a certain request is malicious while it is actually legitimate. In such situations, you can whitelist the triggered mod_security rule on the server so that you can bypass the block. I contacted my hosting, explained the situation, and they whitelisted all the rules that were being blocked by ModSecurity incorrectly.
They did it in a matter of minutes, and everything worked!
