fuel/core — comment on commit 142ee8b0c52dbb7591b35e93b4cb7216d49946ea
File: classes/finder.php line 278
By dhorrigan:

Uri::string() checks if Request::active() is set, if not it returns NULL which is why I made the change here: https://github.com/fuel/core/commit/e7153ba863465ccfc023651357a94a0b0440ce79