Why are some of my apps faded out?

[WPCentral Question]

THis has happened a couple of times since upgrading to WP8.1 on the Lumia 920. Most recently my facebook app has been faded out and the app will not open. My phone is also very slow when I press the button to open the lock screen. I am getting a black resuming screen for about 5 seconds before I can unlock my phone. Any solutions?

 

[SteveSAPA]

That happened to me when I upgraded to 8.1. I think you need to go to the app list (swipe from right to left on the home screen) find the app and it should say attention required. If not go to the app store and try to update the ago and it should say attention required.