Laravel classloader.php error failed to open stream: No such file or directory
This has happened to me in my Windows 10 machine using a 2 years-old Laravel project from bitbucket. If the composer dump-autoload won't work for you, then the error tells you that a directory is missing in my case, there was no migrations folder inside the database directory.
Solution:Create the migrations folder inside the database directory. You can do this using your IDE, or Windows's File Explorer. If your using Git Bash, cd to your project's database folder then do mkdir migrations to create the missing migrations directory.