Fixing the 500 Internal Server Error in WordPress

The 500 Internal Server Error is often caused by plugin or theme functions, but it’s exhausting the PHP memory limit in my case.

So, I need to increase the memory limit.
Here is how I increase the memory limit for my WordPress site:

Find the wp‑config.php file and search this comment line – That's all, stop editing! Happy blogging.

Then, add the following code above the comment line.

define('WP_MEMORY_LIMIT', '256M');
/* That's all, stop editing! Happy blogging. */

Then go to cPanel and look for MultiPHP INI Editor. Select a location on Basic Mode, change the memory_limit, and save.

This solution works for me!