@bmartino1: It's not about posting links. Try to write any message here with the word
"сurl" (do not copy and paste, just type it manually) and you will get that error when you try to post it or preview it. I think Rejetto banned the word "сurl" or somehow that word is crashing the forum (giving the error you posted). I'm using a shady "trick" to write that word (using a so called Cyrillic
"Homoglyphic" character), changing only the "c" of "сurl". It's really weird. And if that word is contained in a link, the forum gives that error too (that's why I was forced to use a short link generator).
It took me almost half an hour to find the word causing this error...