copying personal DVDs to an external hard drive

I am guessing that the disc image that only plays is the first one that you select to play.

( SOMETIMES) If you still have the first disc image mounted then this one will play even though you attempt to play other disc images.

So try this.

Unmount the current disc image before playing other disc images.

Only have one disc image mounted at one time.

To unmount disc image just drag it to the trash.

DVDs can be temperamental and are rapidly becoming obsolete . . . Apple considered they had gone the way of the Dodo over a decade ago.

So the best way to preserve them is to copy them to an .mp4 format using HandBrake, an excellent free app.

The file size is much smaller than DVD and the quality is virtually the same.

You will then be able to play your videos on your computer, tablet, phone or TV (if they are stored on a USB stick or hard drive). You will also be able to upload them to the cloud so that your friends and relatives will be able to download or view them from anywhere in the world . . . all completely free of charge.

HandBrake has its 20th birthday this year and is an excellent free app that has been used by many of the people on this forum and millions of others worldwide.

Download it from here . . . https://handbrake.fr/

Ian’s suggestion was to convert these old dvd to mp4 files. I second that, as well as the use oc HandBrake to make the conversion. You can easily create a batch and do them all in one go. Tben you will have, ax Ian said, files that play almost anywhere (mac with Quicktime Player; pc; phones; tvs…) and should remain playable for the foreseeable future.

How is the external drive formatted?

Al