I was contacted by someone who was having trouble saving a mailing, get this error in CiviMail:
I ended up comparing the version that saved with the version she had pasted in (which had some content additions) and then line by line (word by word) deleting the newly added text to try to identify a problem. It turns out it was the word "Reunion". I would delete the word and drafts would save, test emails could be sent... I would type the word back and the error would recur.
I've tried this on another install and had no problem using the word reunion so I am totally stumped as to how this could possibly occur. Any ideas?