500 Internal Server Error AGAIN!

This is my previous post:
https://wordpress.org/support/topic/500-internal-server-error-only-on-wp-admin?replies=4

the solution was simply clearing the cache and cookies. but now it is more than that. i still get the 500 internal server error when accessing wp-admin of my website but when i deactivate a certain plugin it works!. the problem is, this plugin is required for the theme to work.

What should i do?, do you think the issue is from my host? or just from the theme?

Theme is: Ripple
Plugin is: PixelThrone