If you're talking about the Playstore. Try scrolling down to Apps in the phone settings menu. Then scrolling down to Playstore, tap on it, then tap on Storage. Then tap on clear cache and data.
Come back out of settings to your homescreen. Then relaunch the Playstore app. That should hopefully fix it for you. I had that happen to me a while back. It's not done it since I did the above method.
