Can't update my Xperia Z1

[nelze]

I just bought a brand new Xperia Z1 in ebay. I ran the first update fine (681 I think), then it notified me that I had another update, 14.3.A.0.757. Whenever I would try to update, it will just keep on downloading the file then give me an error saying "Could not verify." I never had this problem updating a phone (been an android user for 4 years), so I don't know what's wrong. My internet connection is excellent. The phone is also not rooted, I only had it for less than a day. The only major thing I did (which is hardly major) is uninstall some of its stock apps which had the option to be uninstalled (like twitter etc. not the sony apps) Any tips? Thanks!

 

[nelze]

I also changed the launcher and icons but I don't think it matters. Anyone have any idea?

 

[Orlan2]

try to update through the Sony PC companion or to do a firmware repair, in any case given this could solve the issue