Laravel error: "The only supported ciphers are AES-128-CBC and AES-256-CBC with the correct key lengths."

The following error can appear when deploying a Laravel project. Thankfully it's an easy fix.

"The only supported ciphers are AES-128-CBC and AES-256-CBC with the correct key lengths."

It means that the project is missing an ".env" file. Usually you can rename ".env.example" to ".env".

Read more about PHP Laravel env files.