Why does every app switch to advertisements every time????

[AC Question]

After the update, every app I touch goes straight to an advertisement of some sort, mostly video for Sprint, though I'm with AT&T, and I cannot find the culprit. My local AT&T store either couldn't or was unwilling to help, so I am completely clueless as to what in the world is suddenly going on with my Galaxy S4!!!!!!!!!!

I'll tap an app icon, and it'll proceed like it's going to go as usual; the screen will fade, and then suddenly there's a 15-second advertisement for Sprint or some other item. This has even happened when I'm looking through my contacts and call log.

PLEASE HELP ME!!!!!!!!!!

 

[B. Diddy]

Welcome to Android Central! Was this a system update pushed by AT&T? Did you buy your S4 through AT&T, or did it originally come from Sprint?

Try booting into Safe Mode--do the ads still occur? https://support.t-mobile.com/docs/DOC-11724