[AC Question]

Galaxy S4 Active - since latest update i continue to get error messages when apps update or try to add an app

[STARGATE]

That's the unfortunate true for many devices with 16GB or less.
You'll need to transfer all your pictures and videos to a computer or an external storage device.
Turn the phone off for a few minutes and turn it on and try updating apps again. If it still gives you the error than you've reached the limit of memory allocated for apps.
That means you'll need to delete a few apps that you don't use or need anymore.