[Noughty]

I can't repeat the error anymore. Did a bunch of catalogs and no errors. But in descriptions there are no comments (no blurbs). Formats, cover publish year etc are all there but not comments.
And I get no error.

Update. No errors now and description on too. Apparently description note was empty. No idea what it is and how it's different from the merge with comments. But seems to be working fine now.
Update2: It seems that the merge with comments makes it ignore the comments and not the description note. When I select shelf column which has hierarchical tags. Other make it ok.

So the problem is hierarchical tags probably when you want to merge them with comments.