All Calendar entries lost after upgrade to 10.13

[dudleybrooks]

Yesterday I upgraded from 10.10 Yosemite to 10.13 High Sierra. Everything seemed fine ... but when I opened Calendar, every single entry and almost every calendar was gone!

I tried restoring from Time Machine, using the backup created just before downloading 10.13. It restored every entry up through early in 2014 ... but nothing since!

I tried restoring the same pre-upgrade backup again, to see if it would work properly this time ... but this time every entry was once again missing.

I tried restoring from the backup made the day before that one ... and again the calendar was empty.

(Needless to say, my calendar was just fine before the upgrade.)

To be honest, I really want to revert to 10.10. But that's such a major undertaking, that if I can get all my Calendar entries back I'll be happy to stay with 10.13. So I want to try absolutely everything anyone can think of to restore Calendar. But if nothing works, then I'll take the trouble to revert to 10.10 ... and hope that that won't destroy Calendar!

I backup to Time Machine every night (plus just before upgrading), so I don't understand why those backups didn't work.

BTW, I did not sync Calendar (or anything else) to iCloud -- for reasons I won't bother to go into, unless someone absolutely insists. So I can't get Calendar back from iCloud. And I definitely still do not want to sync to iCloud in the future.

 

[BrianBaughn]

Not sure if this will work, but give this procedure a shot...hopefully, High Sierra will be able to open and convert the old Yosemite calendar databases:

1. Quit the Calendar app.
2. In Finder, hold down the "Option" key and select the menu item Go>Library. You can release the Option key now.
3. In the Library folder, you will find a folder "Calendars" that contains your current calendar data in database form. Open the Calendars folder and delete all the files and folders in the folder.
4. With the Calendars folder still open, open Time Machine and travel to a time when you had all your calendar entries.
5. Restore every file and folder from that time into your current Calendars folder.
6. Restart your Mac and then open the Calendar app.

 

[dudleybrooks]

Brian --

Thanks! You (perhaps unknowingly!) gave me the real solution to the problem!

What I had tried before was deleting (or renaming) the Calendars folder and then restoring it from Time Machine. I hadn't tried what you suggested, separately restoring every folder it contained, because it would be so time-consuming. But I was about to try it ...

... THEN ...

... I saw your Step 6: "Restart your Mac." (Duh!)

That was the one thing I had never done!

So, merely keeping the restored Calendars folder from yesterday, and not having to restore anything else, I restarted the computer ... and my Calendar was once again complete!

I had forgotten that some changes only "take" when the computer is starting up.

So, thanks a bajillion!