On my S5, when I am leaving my contacts (e.g.after having called some one) the Play store opens always ever, showing me the App 'Next launcher 3d shell lite'. This is quite a while now and I can not remember when it starts. Since about a month now it even starts when doing other things like checking which apps are still opened through the button left of my home button. Anyone got an idea how I could get hold of this problem ?
I think it is caused by some third party app ,to confirm this call someone in safe mode and see if playstore is started.
If the problem is not in safe mode ,It is confirmed that it is caused by a third party app.
Now you have to guess which app is causing this issue but rather than guessing you could see running apps in process status which is located in developer options.
Or you could check application manager and in running tab see any unknown/strange/untrusted app.
After un-installing that app I hope your problem will be solved.
Hope it Helps.