Android 5.1 Lollipop update stuck

[futureishere]

I got a notification for Android 5.1 Lollipop update for my phone. I downloaded the update but it is stuck in installing phase for more than 12 hours now! I have tried restarting the phone but after the restart, the phone automatically starts the system update again and is still stuck. What can I do?

[Thommo]

Try performing a system repair using PC Companion as this will often fix issues - This will factory reset your phone and erase all data

Switch off your phone and unplug from Pc (Hold volume up and power for around 10 seconds)
Start PC Companion and select Support zone then Update my phone/tablet then in Blue Repair my phone/tablet and follow the on screen instructions - When prompted connect your phone still switched off holding volume down or back button - This should start the repair or reformat process

If you are using Windows 8/8.1 or a 64bit operating system then adjust the settings for PC Companion and run in compatibility mode and chose Windows 7 or XP

[Chris___a]

Hi,

I've got the same Problem. Is there any way to Do this without PC-companion? I Do Not own a windows-pc, only Linux.

[Tdvir]

I also have the same problem. Is there any way to fix it with out erasing all data?

[futureishere · Accepted solution]

I was able to fix this problem by just doing the update process from PC companion again. I didn't have to erase my data.

[HKBsony]

Same problem here...

[Politelorna]

Been updating for 6 days!!!

[7bonsais]

Mine too, for over a week now. I've tried everything but don't have access to a pc.

[cobbler]

I updated via wifi from kitkat 444 to Lollipop 511 and all went well apart from the very last update which didn't take too long but said it didn't install successfully, thing is if I go to settings it tells me my system is up-to-date. 

If I go to Settings ----> About Phone ----> Software Update, then hit on the three dots top right hand side, then update history, this brings you to the Xperia System update of which when tapped on brings up this image below. It looks like it is actually installing as there appears to be movement underneath where is says the word installing. Nothing happens if I just leave this, let me say that I never saw anything like this untill the very last reboot while updating.

I was wondering if perhaps this was related to the message I received prior to the last re-boot when updating, the one that said unsucessful but didn't ask me to update it again whatever it was.

[cobbler]