Error like "Node type "" does not exist"

About a year ago I made a site on Neos 1.2
On the site works editor with access "TYPO3.Neos:Editor"
Now I see error like “Node type “” does not exist”.
I removed the empty Node type from DB, but it did not help. I can’t export site. Help me, цhat should I do

What did you do before “Now” ? Did you change anything on the setup, ugrade, … ? Look really strange if this message pop up and nothing change recently in your project.