From documentation:

All the QCRML files need to be located in c:\resource\qt\crml directory in Symbian file system.

This is ok when Qt is installed on the phone, but when Qt is in the phone ROM, this is a problem.
QCRML files should be placed in z:\resource\qt\crml when in the phone ROM.

The easiest way to do this is to search all drives, e.g. using Symbian's TFindFile