[sufiyan irfan]

i have 640 xl and i have upgraded it to windows 10, whenever i try to add or save any contact in people by touching the plus sign..... the contact window just pops up and then app is closed.....its pathetic coz i dont have any contact in my phone now... i am trying to revert my phone to windows 8 and it is also not happening :/

[jmshub]

If your contacts are all suddently missing, it sounds like your Primary Microsoft account isn't logged on properly. Go into Accounts in Settings, and make sure that "Attention Required" isn't on your Microsoft account.

[sufiyan irfan]

the problem is i cant save any contact