“open_basedir restriction in effect” errors mean the host is very restrictive in terms of php configs. The open_basedir setting prevents scripts from reading files (via requires, includes, any of the file handing functions, etc.) from directories that are not marked as “safe.” It was designed to prevent users from accessing sensitive files and/or other user’s files shared servers while PHP was running as “nobody.”
If you have Cpanel or Plesk, etc., try switching to the CGI version of PHP using suPHP. But if you can’t, find a new host.