I'd guess that you're getting that because the post is over the size limit, gets truncated, and the truncated post has unclosed tags. Note that it's difficult to exactly calculate the length of a post as the forum sees it, since various conversions are made before counting; for example, "  " (two spaces) actually counts as 7 bytes for length-limit purposes because it's converted to "  " before counting.

Try removing https://bitcointalk.org from the links to make the post shorter. These are the same:
17740024