I'm very computer illiterate. Tried to post in General Topics twice and it won't let me.
If you can post other things in that forum then it's probably something in the post that is triggering the board filters. Try this:
Write (or copy & paste) a small portion of the whole post - a paragraph or a couple of sentences - then click the preview button. If it shows you the preview, everything is fine with that part.
Add a little more and click preview again. If it shows the preview then that part is fine. If it gives you an error message then there is something in that last part that is causing it.
Keep adding a little at a time until you get an error message. Then look at the part that triggered the error to see if you can figure out what is causing it. It can be what appears to you as a perfectly innocent word.
Okay. Thank you!