Re: Problem w/ creating groups. Avatar step and Group Blogs does not work, can’t complete.
I should think the second line in that error log is the problem. open_basedir restriction is something – I believe – that web hosts will employ to ensure safety protocols between different sites on same shared server, it essentially states a directory within which scripts are permitted to run, and in this instance is possibly proving too restrictive.
You will probably need to open a ticket with your web host and ask them what restrictions are in place, mention the above and ‘PHP Safe Mode’ and ask them if anything can be done to rectify the issue their end, also it may simply be a group permissions issue where you do not have apache as owner of the directory and therefore are trying to perform actions as a group that is being denied.
Not sure if this will help but it’s sounding more like server issues than BP/WP and if you are on shared hosting it will be best to see what your web hosts can resolve for you.