Photo curation process is stuck since 8 months

How large is your Photos Library?

The curation is needing a very long time. For my smaller test libraries with just thousand items or so the "Curation" finished within a few days, but for my larger iCloud Photos Library with with more than 50000 photos and videos the curation never finished between system updates on any of my three Macs, there is just too much to do and the background processes will start over when we import new photos, delete photos or edit photos or mark favorites.

But we can work with photos while the "curating best photos" is done. This is only necessary to compose the tiled layout of the Days, Months, Years. I rarely look at the tiled layout in the Days anyway, as it it not possible to recognize the photos I am looking for, when they are tiled, and and it is not possible to show the titles in the tiled view.

If your library is small, Photos should have completed the "curating" by now, unless you keep importing new photos to the library. Perhaps there is an item in your library that cannot be processed by Photos. You may want to check for referenced files, or items unable to upload as described here: Check the status of your library in Photos for macOS - Apple Support

Photos or videos in a legacy format that cannot be processed need to be removed and replaced by more compatible versions, or the background processes can hang.

Have you checked the system status?

Are there any videos or images in a Legacy format, as listed here for iMovie? About legacy media in iMovie for macOS - Apple Support. A single video or image file in a format that is no longer supported in your current system version can cause the background processes to get stuck.

I tested all my videos by exporting them with "File > Export > Export unmodified original", and then tried to import the exported files into a new, empty Photos Library. Any video giving an error message should be removed from your Photos Library and converted to a more compatible format.

1) Quit Photo (system library).

2) Hold the option while launching Photo.

3) Choose a different library.

4) Wait for Photo to launch.

5) Quit Photo

6) Hold the option while launching Photo.

7) Choose your system library.

This should fix your problem.

injeet, We recommend that you contact Apple Support directly so that they can work with you to find a solution. You can reach them by clicking here: Apple Support or calling the most local number in your region: Contact Apple for support and service. Thank you for participating in the Apple Support Communities. Cheers!

Hello injeet,

Welcome to Apple Support Communities. 

We understand that your photos have not completely uploaded to Photos. We are happy to help.

Have you completed the troubleshooting steps in the support article that brought you to us? If you have and there’s still no resolution, please contact Apple Support here: GetSupport

These steps may help. Let us know if you have further questions.

Take care.