[@robin-w Moderator 12 years, 2 months ago]

could be many things

lets start by eliminating plugin and theme

It could be a theme or plugin issue

Plugins

Deactivate all but bbpress and see if this fixes. if it does, re-enable one at a time to see which is causing the error.

Themes

If plugins don’t pinpoint the problem, switch to a default theme such as twentytwelve, and see if this fixes.