Why can I not insert foto

One more thought? Is your Photos Library syncing with iCloud Photos?

In that case you need to download the photos from iCloud, before you can use them in other applications. View the photo enlarged to force a download.

Hello Ploate,

Welcome to Apple Support Communities! It sounds like you're having trouble inserting photos into an album. I'm happy to assist you with this.

Make sure you have your System Photo Library designated properly by following the steps in this article:

Designate a System Photo Library in Photos

You can also test to see if this happens when you try to move photos into other applications.

Try a new user account also to hep isolate the cause of this issue:

How to test an issue in another user account on your Mac - Apple Support

If this is set up the correct way and the issue persists, contact Albelli for additional assistance:

https://www.bonusprint.co.uk/albelli-has-become-bonusprint

Best Regards.