Can't Install apps

[Shreyan]

I've updated to lollipop but can't install some apps like instagram, vodafone app, traffic rider n all from play store also tried side loading them... I've also factory reset the phone many times. But it won't work. Please help...

 

[hang-the-9]

Need some details here, is the phone stock or rooted or hacked in some way? Why can't you install the apps exactly? Need details.