Rutas absolutas. Claramente. Estaba usando esto:
$raiz = $_SERVER['DOCUMENT_ROOT'] . $_GET['folder'];
y cambie la variable por "..". Ahora funciona.
Pero todavia tengo otro error, tanto en local como en 000webhost.
Cita: Fatal error: Uncaught exception 'RuntimeException' with message 'File not writeable: ../MeshRepository/album/Characters/horse_mayid.jpg' in /home/a6118506/public_html/MeshRepository/libreria/miniaturas/GdThumb.inc.php:626 Stack trace: #0 /home/a6118506/public_html/MeshRepository/libreria/script.php(75): GdThumb->save('../MeshReposit...') #1 {main} thrown in /home/a6118506/public_html/MeshRepository/libreria/miniaturas/GdThumb.inc.php on line 626
Cita: Warning: move_uploaded_file(../MeshRepository/album/Characters/aeer_abress.aoi) [function.move-uploaded-file]: failed to open stream: No such file or directory in C:\wamp\www\MeshRepository\libreria\script.php on line 81
Warning: move_uploaded_file() [function.move-uploaded-file]: Unable to move 'C:\wamp\tmp\phpCD9.tmp' to '../MeshRepository/album/Characters/aeer_abress.aoi' in C:\wamp\www\MeshRepository\libreria\script.php on line 81
Error when saving the file!