When users try to share their location with someone using iMessage, they may see a message that says, "The location isn't available." This is because of a default privacy setting that Apple has turned on. You must turn this setting off to share your location via iMessage. To do this, open the Settings app and go to Privacy > Location Services. Scroll down and find Messages, then make sure the switch is turned to the On position. Now you should be able to share your location without any problems.