same trick to see which half of that (1/4 of the whole thing) is the problem. By chopping halves of halves it does not take long even with a long message to find the culprit. When you find the problem segment or word just use a different word or way of saying what you are trying to post.

If posting a pic, I suspect the file name might also be the problem. Save the pic with a different file name and try again. I have not done this in quite a while so there may be other problems like having multiple uses of one word in the post or multiple words so I cannot guarantee this will work in all cases but it probably should.

It is easier to move the whole Subject and Text into the Text box with just a 1 in the Subject box to do this so this search and editing you can see the whole thing for easier "chopping", Then put the Subject back in its box and verify one final time that you have eliminated the problem and then post it. Good luck.