error MT1303: Could not decompress the native framework

[picatextra]

Hi, i'm trying to compile the simpleapp-with-framework, but i have the MT1303 error

Process exited with code 9, command:
3> /usr/bin/unzip -u -o -d /Users/......./obj/iPhoneSimulator/Debug/mtouch-cache/MyFramework.framework /Users/……/obj/iPhoneSimulator/Debug/mtouch-cache/MyFramework.framework.zip
3> End-of-central-directory signature not found. Either this file is not
3> a zipfile, or it constitutes one disk of a multi-part archive. In the
3> latter case the central directory and zipfile comment will be found on
3> the last disk(s) of this archive.

Looking in the directory , the zip file is 0 mb

Xamarin.iOS v4.0.30319