Wikitude

File arml error

I can not create a world ARML uploading a file. I tried to create an ARML file (version 1.0) and I get this error: "The file prover is not a valid arm file, please check syntax". I even tried to upload the example file-arml.xml Wikitude and error is the same. I would appreciate help. Thank you very much.

Thanks for responding so quickly.
I saw where the problem was The symbol ?

In my document the header was:

<?xml version=?1.0? encoding=?UTF-8??>
<kml xmlns='http://www.opengis.net/kml/2.2' xmlns:ar='http://www.openarml.org/arml/1.0'

          xmlns:wikitude='http://www.openarml.org/wikitude/1.0'>

-----------------------------------------------------------------------------

I changed to the following code and it works correctly:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"
     xmlns:ar="http://www.openarml.org/arml/1.0"
     xmlns:wikitude="http://www.openarml.org/wikitude/1.0">

---------------------------------------------------------------------------------------

Thank you very much