Invalid Argument / Yaf To Vb

Invalid Argument / Yaf To Vb
I am Converting YAF to vBulletin, and when I try and get the Users Converted, I am getting this error :

Warning: Invalid argument supplied for foreach() in [path]\impex\systems\yaf04.php on line 113

Which is=

foreach ($data_array[‘data’] as $import_id => $data)

I Need this fixing ASAP.

Thanks

Danny