Am having the exact same problem having upgraded. Not only will the timeline I was working on not open, but new ones I create and close will not open. The only one I could get to open was an old one linked to the mobile app but which is the only one that contains a relative path: /Users/me/Library/Mobile Documents/iCloud~app~timeline~aeon/Documents - all the others had absolute paths and none will open.
Thanks for reporting this and our hugest apologies for the issue. We are actively looking into this.
From what we can see so far, it looks like there’s been a problem with the Mac App Store distribution. Can you confirm if you update the app via the app store?
If so, for now we’d recommend installing the app from the direct download on our website:
Please let us know how you go. We’re working to get things fixed asap.
Yes, that’s correct. I opened the app, then got a notification that there was a new version, so updated via the App Store. Then it wouldn’t reopen the file I’d been working on, even after restarting the machine.