Item publishing error cms with editor mode

Hi all!
I made a site for a customer with several cms collections, but the customer can’t create or edit new cms item.

The error message is “publish failed, this item could not be published. re-publish your site to enable single-item publishing”.

I’ve never had this problem before, all my domains are synchronized, my site has been republished several times, the structure of the cms collections has not been changed.

I have no idea what the problem is and I haven’t found a solution on the forum, do you have any ideas?

I’m a bit stressed because everything was working fine 1 week ago…

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