Sure is readable.
-rw-rw-rw- 1 root root 9765 Sep 2 13:59 config.inc.php

If I move the same file back into the directory specified in $thispath, it works fine.

The thing is I dont see any reference to $configdir ubbt.inc.php.

cat ubbt.inc.php | grep $configdir shows me nothing, so if $configdir isnt there, how is it going to know the file location has changed without hacking the file itself? This is the trial version if it makes a difference.