slideshow problem, error message

Check Photos iCloud preference pane and see if you have the iCloud Photos Library enabled along with Optimize Mac Storage. The storage option is what you're running up against. You have optimized versions on your MBA and need to download the full sized version before you can create the slideshow or print or export or…

You'll have to download the originals first and then start the slideshow.

I have the same issue; but this is not a "solution" nor has this "workaround" worked. One solution would be for apple to first fix the incorrect error message; it's not an internet error. Better still fix the error itself. If it's a setting, make the setting obvious and make it work. This is lazy programming. One of many issues I've run into attempting to publish media from various apple apps, imovie, photos etc. Even attaching pictures to a third party email client is needlessly opaque. It was my understanding that the MAC should just work, be simple, be fun. My experience over the years is heaps and "tricks"; painful workarounds and hacks to mainstream apps just like this one to make things that should be really simple, just work... annoying given the resource the company have to make great software. Back to bootcamp to get the work done..

I'm having this problem too. I can't play any length of slideshow without the 'Error downloading slideshow photos' followed by 'Internet Connection Required'

I have changed the setting in preferences to 'Download originals to this Mac' but that doesn't help.

I created an album on my MBA and want to do a slideshow of that, so want to download full-size versions of those, but DON'T want to download the other thousands of photos and videos. How do I download selectively? TIA!

I don't know as I don't use iCloud. But if you try to edit one I think it should start the download for that image.

Apple isn't here. We're all users like yourself. Tell Apple via Feedback - Photos - Apple

Yep I hear you. And thank you kindly for your attempt to help.

If I were apple, I would hang out here to find out what is broken and try and fix it. Surely the best kind of feedback you can get for FREE!! I guess you get what you pay for.

The only way we got to publishing this was to babysit it over hours, hit ok and cancel every time it reported the wrong message (internet connection). On each occasion it would download one or two or sometimes more files then die again.. rinse and repeat.. approx 4 hours of mucking around for a 170 picture, 52 slide, 3.30 min, 350mb output file which even then doesn't allow you to granularly edit the rubbish slides with only one picture or that attempt to apply ken burns to a panorama (which then failed to publish to youtube via imovie.

Apple; if you are listening, please sort this junk out. Not awesome.