500 – Internal server error - WordPress
– 500 – Internal server error message at any point in your website.
This error could happen for three reason:
You have a plugin with an error
If you can’t access your whole backend, then you should open up your ftp, and rename the plugin folder names in your wp-content\plugins\ folder one-by-one to see, if one of them is solving your problem. If you only see the internal server error at the Smart Slider’s page, then you could deactivate your plugins in your Plugins list too.
Bad .htaccess file
Go to your ftp into the root folder, and rename your .htaccess file to something else to see, if it solves the problem. If it does, you can keep it like that, this file is to modify the server’s configuration.
Server setting problem
This is the most common one. It could be, that the timeout settings in your host are too low, and the php code doesn’t have enough time to run, or maybe the memory limit is too low. If the previous two doesn’t solve your problem, then the case will be this, and you need to contact your server host to resolve it.