Solution for WordPress WP Super Cache Plugin HTTP 500 Error

As you can see, this error page is not from WordPress, but customized by the hosting provider. Everything was normal, it’s just because of upgrading the wp-super-cache plugin earlier that caused this error.

Googled it and found many people discussing this 500 error related to wp-super-cache.

Solution: In the backend settings, change WP Super Cache Status to HALF ON. That is, disable Super Cache and only enable basic Wp Cache.