[AC Question]

I just downloaded My HTC one to Android 5.0 Lollipop and I can't start it now cause when I am in the startup screen ''System UI has stopped unexpectedly would you like to send an error report to HTC? '' but what do i need to do cause I cant get into my phone now !!

[Rukbat]

Sounds like a bad update. Bring the phone into the carrier's store, tell them what happened and ask if they can please reflash the update for you. (See if you can see the phone when it's plugged into a computer. If you can, copy any important files to the computer. The carrier may opt to just give you a working phone. [Any important files should always be backed up anyway.])