Forum creation within groups fails

I have created a group within the site as ADMIN, and then clicked on FORUMS within the group and get an error:

File inclusion failed.
Did you properly edit inc/header.inc.php file ?

The error is coming from index.php in the modules/boonex/forum/

Firebug does not come up with anything

I am getting this also - and while there are threads all over the place here with this question, no one seems to know why.

hmm  i'll give it a test and see what happens.

Edit:

all is well for me as admin.  both running 7.0.6 ?

Yes,  7.0.6 fresh install - just checked permissions on inc - it was 555 for some reason but I changed it to 755 - still doesn't work.   Can't get to forums admin at all.

thats odd indeed...  inc should be set to 555 on your type of server...

Something weird is going on - I also found that "allow_url_fopen" error to be commented out and I never touched it - its a fresh install - ghosts.    Are you willing to take a look?