Recent content by Jerry Morrison

The point is, it's time to move on to testing which apps could cause the problem.

Yes, I did: The symptom is a second lock screen that you must swipe to unlock, and people have pretty much ruled out the OS-update hypothesis. How is the symptom different than the DU adware? A screen shot would help. See the steps in Determine which app is drawing on top of other apps? to find...

If your second lock screen looks like the picture here then the problem is the "DU Quick Charger" adware app. The straightforward solution is to uninstall whatever apps secretly installed "DU Quick Charger". The same stackexchange page lists some of the apps which do this, such as ES File...