Maybe an app "froze" the device's operating system and as a result you are unable to remove apps. Restart your mobile device first, and then uninstall the app.
Apps that are part of the operating system cannot be uninstalled as they are important to the operating system. If the app you are trying to uninstall is one of them, you won't be able to remove it.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.