"Attention required. Tap Here" error in sideloaded apps which are more than 20mb

[Arunkumar Sundaramoorthy]

In my Lumia 520, I cannot able to install sideloaded xap files which are bigger in size (~20mb).
Rest of the files installs fine. I tried Resetting my phone. But nothing works.
Any suggestions??:unhappy:

 

[BIGPADDY]

Is your phone developer unlocked if not this could be the issue?

 

[rakesh1995]

??? Screenshot plz

Sent from my Uuusumm Lumia 520 using Tapatalk