Supernatural DVD's - Failed to open disc

[AaahThatWasScary]

Hello everyone and all.

It's my first time using the MakeMKV software and I want to rip (if that's the correct term) my supernatural DVD's.

I have tried it with a few discs and everytime time I get the message that says: "Failed to open disc".

Why do I get this particular message?
Maybe I did something wrong?

The first thing I did was opening the MakeMKV software, after that, i put one of my dvd's from the television series supernatural in the external disc drive.
i clicked on the drive with the disc in it button, the big button in makemkv, and then it says failed to open or something after it read the disc, what do i need to do?

thanks in advance,
have a nice day!


PostScriptum: sorry, i am not from an native english speaking country, i'm dutch, so my spelling isn't the best probably

[gkar_of_narn]

I'd start by getting another dvd or dvdrw drive