Problems with 8.1 GDR1

[WPCentral Question]

So, here's what happened...
i've formated my Lumia 820 and changed the account (just gave it to my brother, it was mine and was working fine). The phone already had wp8.1, and i made his account eligible to the preview update.
After i restored the phone, it updated to the new GDR1, and then it started...
Whatsapp stopped working, when i installed it just stuck on the background screen, loading forever. After some reinstalling, it oppened, but messages take about 3 to 10 minutes to send! and even more to recieve!
If that wasn't bad enough, some weird things started to happen, like the lock button stops working sometimes and the phone just stay locked forever, and even turn off by itself...
Does anyone have any idea about what's going on?

 

[Mattyborges]

Same here. Looking foward for an answer...

 

[Ashish Gupta888]

It could be issues with the SD card. Let me guess if you/your brother have ever tried to move WhatsApp from Phone to SD card and it must have not worked then. You need to uninstall and install it again and see if that works. I have experienced this issue when I did this on my lumia 525. Even today, I experienced the lock screen issue where it stayed on lock screen and did not allow me to unlock!

Resolution: Soft Reset. Power+Volume Down for 15 seconds and your phone will automatically rebooted. After reboot, it will ask to scan the SD card and allow it to scan. You should be all set then.