Photo Library

The Photos Library in the Trash may be created by some app, that is using the Photos.app . As Photos is an app installed by the system as a part of the system, other apps may be calling Photos to use it for image processing. To be able to run photos they will have to create a temporary Photos Library and will trash it again, when done.

Have you moved the library out of the Trash and opened it in Photos to see what is inside? This might tell you which app has been using Photos.

You wrote "The photos are all safe. I can access them from my other apple devices. It is backed up on iCloud.

However I am unable to open it on iMAC. "

To be able to access your iCloud Photos on your iMac, you would have to create your own Photos Library on the iMac. The Pictures folder would be the best place for it. Photos cannot run on a Mac without a Photos Library. It will always create a new library, when you try to open Photos and there is no library.

Do you still have the current version of your Photos Library.photolibrary in your Pictures folder and do you have a backup of your Photos? Just to be sure your photos are save?

Did you move your Photos Library to the trash yourself, and the problem is, that it keeps reappearing, after you empty the trash? Or should the library not be in the trash at all? How large is the library in the Trash? Is it empty or containing photos? Is it a new library or an older one?

I have seen a Photos Library reappear after emptying the Trash, when I deleted a library on an external drive, and this external kept losing the connection and ejected itself. It was gone from the Trash, when the external had been ejected, but reappeared, after the system mounted the external again. If your library is on an external volume, try to empty the Trash, while the external volume is connected.

You‘re welcome 🙂