With what you have posted on two different topics.
The issue is a old version of ubb.
Just guessing since html is enabled someone posted a topic subject with html using less than the characters than the limit. Big security risk enabling html to all.
You will need to provide more details on the posted topic for anyone to help more.
Such as mentioned before. What was entered in the actual post.
Not from a view source.
I would suggest you contact the admin of the site and have them visit this post for assistance.