android.process.acore has stopped unexpectedly

After updating Android I got this error. During update android asked me to move some of app to sd card as there were not enough space for update. I moved some and after update and restart I can't enter contacts. When I press green button for calls (enter contacts) it shows error: android.process.acore has stopped unexpectedly I'm using HTC Cha Cha. I try t reboot phone, to put battery out and back. Finally I try restore phone to factory settings by removing all apps and data. And I still have this error - android.process.acore has stopped unexpectedly Can you please tell me how to fix it without taking phone to service. Phone is brought from US to EU, so I would need to pay service if I can't fix it myself.