Error 500 after clicked on publish button

Hi Support,

I have a strange problem.

In my dashboard, everytime I published a post, I received this error:

“Sorry, that didn’t work.
Please try again or come back later.
500 Error. Internal Server Error.”

The link is: http://ceritadulu.com/wp-admin/post.php

I found the post was published. always published. but why did I always receive this problem.

Has anyone encountered this problem before?