bbPress adds this notice in because you are an admin of the site I believe.
Lynq is right! That warning shouldn’t show up for any of the other users unless they are admins. So there is probably no need to mess with it since you are likely the only one seeing it 😉
On my website, user are not admin but they see HTML content warning. How can I fix it?
Please do not revive old tickets but next time open your own one explaining what issue you have.
Only keymasters should see this message. If you have any plugin that changes capabilities, please review your settings.
If you only want to hide the box then you can play with a CSS code like this:
Or check out a plugin like ‘bbP Toolkit’ that does this too. Just note that both options also remove some other informational messages !