Thanks for answering.
The version is QlikView 11 SR2.
I have found this http://community.qlik.com/message/355929
And as you said I have restarted the Service and it works, but really the solution is to schedule a reset of the QlikView Distribution Service? There is no another solution?
I encountered exactly the same issue as you. It is a QlikView Bug that is corrected in: Ver11.20 SR3.
Please refer to this thread:
Until you apply that version you can manually restart your QlikView Distribution Service every day or two.
Best Regards, Bill