You can try these solutions to fix Unfortunately process android.process.acore has stopped error: (1) Clear Cache of Application. (2) Clear Data and Cache of Contacts related apps. (3) Reset App Preferences. (4) Update Android OS Click Here to find the source with more solutions in detail.
Some Simple Solutions: Solution#1 (1) Switch off your smartphone. (2) Remove bettery and also your Sim Card and wait for some time. (3) Reinsert battery and sim card and turn your phone on. Solution#2 Set your mobile network to automatic . Solution#3 Update your phone software. These solution will probably fix error while searching for networks. Hope it helps.