solution for any "frezze" phone xperia z1and xperia z ultra during or not software update) . just press simultanious volum up and the main on/ff buton for 5 - to 10 sec. Your xperia Z1 or Z ULTRA will be restart . I had this problem with my first xperia z ultra 4 times and then I just bought the new xperia z1.
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