Chapter markers in iMovie leading to Scene Selection in iDVD not working

That last system that iDVD was fully compatible with was High Sierra, 10.13. After that it continuall was less compatible with each succeeding system. You'd be best served by creating an external boot drove with High Sierra and use to when you want to use iDVD or migrate on to one of the many video DVD authoring apps that are available at the App Store.

If you use still photos to create video DVDs along with movie files there are two apps that look promising: Wondershare DVD Creator and DVD Maker Lite - DVD Creator. I've done minimal testing on both and believe Wondershare is easier to use. Both can save the project as disk images and both have demo versions to test before purchasing.

As far as I am aware the Add Marker feature in iMovie 10 is not a Chapter Marker , so this will not be "picked up" in iDVD.

If chapter markers are present then you would be able to see them in your exported file from iMovie in QuickTime Player like this

Chapter Markers could be placed in older versions of iMovie but ceased with iMovie 10.

Could you try different themes to see if they behave differently.

I have just tried Centre Stage Main and obtained the same as you, but most others seem to be OK.

This may have something to do with a known problem with some animated themes in the newer OSs.

If you do try different themes then it is best to start each one from scratch, rather than changing an existing one.

This is because it is a known problem that changes are not always recognised in iDVD, irrespective of the OS.

Let us know how you get on, before pursuing the idea of the external drive.

Make sure you are comfortable before doing this and seek further advice.

https://blog.macsales.com/36128-yes-you-can-use-one-drive-for-time-machine-and-file-storage/

My results are using El Capitan by the way.

What I am describing here is a method to get your movie ( the .mov file from your iMovie 10) into iMovie 6 without transcoding, then add chapter markers, then drag the iMovie 6 project into iDVD, without the need to export out of iMovie 6.

The following may seem protracted, but it is only a few mouse clicks.

I will call your .mov file from iMovie 10 "the movie file".

Open iMovie 6 HD.

Create a new project by selecting" a new project" if it pops up or File>New and select Desc Top for the project.

Do not import anything but just Quit iMovie HD and you should get this on the desktop.

This is the iMovie project(My Great Movie 1) that you just created, but it has no movie file in it yet, so we will put it in.

Control click on the project and select Show Package Contents.You will see a Media Folder

Drag the .mov file( the movie file) into the Media Folder .

Now close out of this Package contents.

Now double click on the iMovie project above to open it in iMovie 6.

When it opens you will get a pop-up saying there are some stray files . Select VIEW TRASH.

Drag the movie file that is shown to you into the time line at the bottom.

Select the Chapters menu bottom right and place the play head at the desired point and select Add Marker.

Repeat for more markers.

When finished adding markers Quit iMovie HD and Save.

Open iDVD and drag the iMovie Project File above into iDVD.

You should see the Chapters /Scene Selection displayed providing iDVD preferences are set as you have described earlier.

Hope I have covered everything.

I didn't get the link to screenshot.You can add image insertion from menu at bottom of reply box.

Click on the "show the DVD map " button at the bottom. Do you get any error messages?

iDVD has become problematic with later OS upgrades and some have moved the iDVD application to an external drive to solve some issues.Not ideal but see this

https://discussions.apple.com/thread/250109226

From what you did above, was this from selecting the "preview DVD playback " button? ( looks like a play symbol).

I wonder if the chapters would appear on the disc image, FILE > Save As Disc Image.

Play the disc image in DVD Player by mounting the disc image and open DVD player.

Others on here, Old Toad and Rich. may chime in, so let us know.,

And another.

If you have got Encoding set to Best Performance go up to top Advanced and uncheck Encode in background.

Another thought.

To check if the addition of chapters is affecting the ability to burn in iDVD you could try this.

The following is to bring your original video file that you dragged into iMovie 6 into iDVD.

In other words your original file before adding chapter markers.

With a new project set up in iDVD, control click on your iMovie 6 project >Show Package Contents>Media.

In this media folder is your video without chapters.( remember that you dragged it into there earlier) .Drag it into the new iDVD project and see if you can create a disc image.

If you get the same Multiplexer Error then the issue is probably to do with the video rather than the chapters.

Have you ever had iMovie 6 HD

If not see this.

https://discussions.apple.com/thread/250972575

Not sure if it will run on Mojave.

If you can get iMovie 6 running on you Mac let me know, I will give instructions for easy chapter markers that does not require additional exports.

Out of interest, if you had Encoding set to Best Performance did you go up to Advanced and uncheck Encode in Background.?

I was able to reproduce the Multiplexor error that you had with Best Performance and Encode in Background checked with a tick.

Set best Performance in both iDVD >Preferences>Projects>Encoding and Projects>Project Info >Encoding just to make sure.