I've already tested many queries with Saxon succesfully, but today every query I want to process, it leads to the same error :

net.sf.saxon.trans.DynamicError : org.xml.XASParserException : Premature end of file.
Query processing failed : Run-time errors were reported

The execution is done by a command like :
c:/saxon> xquery -o books.xml -s sortie.xml query.xql

thanks for help !