If you are testing something new, there is always chance to break things, that's why you should always have a fail-safe system. Thing is sometime situation could be a bit different. I decide to test “WP-Rocket”, so disabled W3 Total Cache. I will write a separate article about my experience with “WP-Rocket”. Soon, when I decide to revert back to W3 Total Cache, I started to get weird errors, here I will explain how I solved it.