Note : Following examples are tested on FireFox Version 52.

Open Web browser console. F12

Method 1 . Press F12 and click on "Console"
Method 2 . Press Ctrl + Shift + K

All views templates can be overridden with a variety of names, using the view, the display ID of the view, the display type of the view, or some combination thereof.

Run cron by drush

drush cron

Add cron hook to a custom module.

/**
 * Implement hook_cron()
 */
function MYMODULE_cron() {
  // Your codes.
}

To make a redirection after user login, we can use the hook hook_user_login().
Note : You cannot use $form_state->setRedirectUrl() directly in the form alter, since it will be overwritten by UserForm::submitForm().

The website encountered an unexpected error. Please try again later.

This is a generic message. To find the problem refer to server log. (For example : /var/log/apache/error.log on apache)