Facebook App - 'Newest Blog' Section Pulls 'Warning: array_key_exists()' Error

[Mondi]

Hi all -

Thought I was 'there' but my newly installed Facebook App here seems to pull the following error when a 'Newest Blog' ['Newest Blogs Section'] is opened here:

Warning: array_key_exists() [function.array-key-exists]: The second argument should be either an array or an object in /home/*domain*.com/public_html/*app-file*/category.php on line 2053

This doesn't seem to pop-up when opening threads ['Friends Activity'] or any of the forums ['Forums'].

Can anyone tell me how to solve this issue?

Thanks in advance -

Mondy

PS: Question also raised at vBulletin here: https://www.vbulletin.com/forum/show...ts%28%29-Error