Booting failed: The selected file or folder is invalid or corrupted.

Newbie here!
Sorry if my question is easy or dumb!

Here are the steps I've taken:
- Download and install RCPS3
- Install Firmware
- Copy and paste files from my game's Bluray disc
- Click on "Open" icon in RCPS3 and select the folder containing game's files.

I get this error:
Booting failed: The selected file or folder is invalid or corrupted.

I tried reading the quickstart guide, but maybe I'm missing something.
Can you please help me?
A step-by-step instruction would be highly appreciated!

You can't copy files directly from an encrypted disc, you need to follow the instructions on the Quickstart Guide to dump your disc. The dumping process on the guide is described step by step, use the PS3 Disc Dumper and it's a two click process.