I tried everything. Reseted the watch several times as described above. Restored the iphone to factory defaults several times (a brand new phone, i had no data to lose). Reseted the wifi network in my house. Tried with my neighbors wifi network. More than 5 hours of trying dozens of solutions. Nothing. Finilly i changed the region and the language on the phone (i live in Spain, changed it to English and region Canada). I couldn't freaking beleive it, it started updating right away. So simple and so weird.