Hi Hamed,
The error here is because your gct file was saved as UTF-16 encoded text which is not supported. You'll need to re-save your file as UTF-8 encoded plain text, then the file should load.
If you're using windows and open the file in notepad, UTF-8 should be listed in the "Encoding:" drop-down next to the save button (note that the one you want is just UTF-8 and not UTF-8 BOM).
-Anthony
Anthony S. Castanza, PhD
Curator, Molecular Signatures Database
Mesirov Lab, Department of Medicine
University of California, San Diego