 <p>As hakre said in the comments and as it's stated <a href="http://docs.kohanaphp.com/general/libraries" rel="nofollow" title="Libraries">here</a> "Library class names and file names begin with a capitalized letter"</p> <p>I changed the file and class to start with C and that fixed the problem.</p> <p>When I moved the project to Ubuntu I changed every file name to lower case, in the case of Libraries that was wrong.</p> <p>Thanks to all and I hope this helps anyone in the future.</p>