"Ultra Stamina Mode Repair": Z3 keeps restarting

[juncto]

Hi,

Since a little while I am owner of a Z3. Unfortunately, I can't use it because of the following problem. After I turned the Ultra Stamina Mode off, I get a pop-up that says: Ültra Stamina Mode Repair" Then my phone turns off and keeps restarting.

Please, can someone help me? How do I solve this? It's really annoying and frustrating :(.

I hope to receive some useful replies, thank you.
 

[Thommo]

Try performing a system repair using Pc Companion as this will often fix issues - This will factory reset your phone

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 onscreen 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

[juncto]

Thank you for your reply. I tried to connect with the PC Companon but when my phone turns off the PC Compagnon can't connect. The phone isn't found.

What to do now?

[Thommo]

You aren't following the guide your phone must be off and disconnected from your Pc as per the guide wait for the connection prompt the hold volume down and connect remember your phone must be off

[juncto]

Thank you very much! It worked

[Marlinajane]

im using windows XP hence PC companion nor Xperia companion is not supported.

Im having trouble the same as above which my Xperia Z Ultra suddenly on Ultra Stamina mode repair.

Please how can i stop this. It so annoying and last for few minutes only

[Marlinajane]

or is there any link for downloading the PC companion

[Marc999888]

Ultra Stamina Mode Repair

Z3 cannot restarting

[Uliwooly]

Do elaborate @Marc999888