How do I move a site to a new server? How do I move a site to a new server?

I have a backup file for the database content and all the files. I uploaded it using cPanel to the new server, imported the database, and updated the username and password as well.

For some reason, the website is just showing this message. 


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


The content of the error log provided by my hosting provider is the following.



How can I fix this?
It seems that you may forgot to move the vendor directory to the new location. Also you may need to run composer dump-autoload to update the autoloader with your new vendor's path. Though may be obvious to many, you need to clear the Drupal cache, in this case I prefer do a truncate over the cache bins (assuming you're using the default cache backend).

Update

Also worth checking the autoload.php file in your Drupal root, this file includes the actual autoloader generated by Composer.