Bug 155509 ModuleHandle findResource method does not support .properties files
There is no fileType for .properties files in IResourceLocator
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
String nameValue = (String) s.getProperty( nameMember );
			if ( !names.contains( nameValue ) )
			{
				list.add( s );
				names.add( nameValue );
			}
		}
		List theLibraries = getLibraries( );
		int size = theLibraries.size( );
		for ( int i = 0; i < size; i++ )
		{
			LibraryHandle library = (LibraryHandle) theLibraries.get( i );
			if ( library.isValid( ) )
			{
				iter = library.getFilteredStructureList( propName, nameMember )
						.iterator( );
				while ( iter.hasNext( ) )
				{
					StructureHandle s = (StructureHandle) iter.next( );
					String nameValue = (String) s.getProperty( nameMember );
					if ( !names.contains( nameValue ) )
					{
						list.add( s );
						names.add( nameValue );
					}
				}
			}
		}
		return list;
	}