That is a bit confusing. I thought it might be the emoji but that works for me.
It’s also not clear why the filename that it’s saying doesn’t exist is longer than 20 characters.
Could you go into iA Writer and tidy up the files that have been created by the action (delete them and then choose another file to look at). I saw a similar message to the one you’re seeing, but it was in iA Writer not Drafts. I think it happened because I had deleted the file in IA Writer on my Mac while still having it open on my iPad. Tidying up the files before running the action should avoid that problem (which I’m hoping is linked to yours)
Dave