Namecheap - (Wordpress) how to fix/resolve "Updating failed. The response is not a valid JSON response."

You have just set up a brand new WordPress blog with a brand new WordPress theme, and you are beyond ecstatic to begin experimenting with them. When you try to post, you unfortunately receive the following error: 

"The update did not succeed. The response cannot be considered a genuine instance of the JSON format."

I have spent a huge amount of work into attempting to solve the issue; but, I have not been successful in doing so. After exhausting all other options, I decided to get in touch with my hosting company, and they fixed the problem in within two minutes.

If you are using Namecheap, it's not your fault. The problem with ModSecurity was caused by the fact that they have their servers extremely well protected.

Here is how you are going to solve it: start a live chat with them and ask them to whitelist or check the ModSecurity that blocks the Wordpress

Simply enough, it will save you a lot of time digging through and reconfigure that on your server. They will simply solve it in 1-2 mins.

For those who wants more technical details, I captured some of the chat with them as below.

"It appears there are some ModSecurity rules which result in blocks for your site. We installed ModSecurity to increase the security of our servers. It is an Apache module which works as a web application firewall. It blocks known exploits and provides protection from a range of attacks against web applications. Its activity may cause such issues from time to time when requests sent to the server match ModSecurity rules. Sometimes such requests are false-positive."