How to Fix It Conventionally When Apple ID Won't Sign In Solution 1. The date and time do not match the actual time.There was an error setting up iMessage or FaceTime.A poor Internet connection prevents you from connecting to the iCloud verification server.Apple servers are down due to network congestion.You have entered an incorrect Apple ID or password.Go to check which is the culprit of your problem. Here list some possibilities that lead to the signing failure. The reason why you can't sign in to Apple ID might be various. Advanced Ways to Fix Apple ID Could Not Sign In Issue Reset All Settings and Factory Reset iPhone Solution 7: Modify Date & Time Settings.Reset Your Apple ID Password and Resign In Check Internet Connection and Reset Network Settings
Traditional Ways to Solve Apple ID Signing Error
