All pages showing source code and a model error

[eluser]linkzao[/eluser]
Hi there.

I'm building a codeigniter app and i was using xampp 1.7.1 with php 5.2.9. Everything was working great, but i recently upgraded my xampp to 3.2.1 and php to 5.4 and then my nightmare begun.

When i enter in any page, i get a blank screen with all my source code and the following error:

Fatal error: Class 'Usuario_model' not found in C:\xampp\htdocs\site\system\core\Loader.php on line 303

i've just tested my other codeigniter apps and none of them are working.

Is there any compatibility problems between my CI version (2.1.3) and php?


Thanks.