bbpress is suffering from issues with themes and plugins following the release of wp4. One issue is that bbp-has-replies sets the ‘s’ (search) variable even is there is no search (it then sets it to false).
This seems to now be handled differently in WP4, and this causes WP v4.0 to tell s2Member (and other plugins) and some themes that is_search() is TRUE , when actually it is not, in the case of bbPress. wp4 takes the existence of the ‘s’ as meaning it is true, rather than examining it’s value.
where this causes the first topic not to be displayed, this plugin should fix that issue as a workaround
1. Download this plugin using the link below
2. Go to Dashboard>plugins>add new
3. Click Upload, and select the file ‘bbpress wp4 fix.zip’
4. Click install
5. and then activate