[@robin-w Moderator 5 years, 11 months ago]

ok, can only suggest you try this, and then discuss with your theme author

it could be a theme or plugin issue

Themes

As a test switch to a default theme such as twentyfifteen, and see if this fixes.

Plugins

If that doesn’t work, also deactivate all plugins apart from bbpress and see if this fixes. if it does, re-enable one at a time to see which is causing the error.

If you cannot do this to your site (say because it is live) then use the ‘troubleshooting’ features of this plugin to let you test without affecting other users

Health Check & Troubleshooting