Kevin:
Sorry about the inconvenience. I've replaced the "embedded forum" option with a simple link and added some text to explain the situation.
Many years ago, someone accidentally clicked the "Adult Content" button. Once that label has been applied, Google will not remove it. I can assure you that there is nothing obscene behind that ominous warning... but alas, the warning remains.
I regularly decide that I'm going to start new forums. Then I immediately decide I'm not willing to lose the years of history. Repeat every few months.
Mark