Socket error in Android Build

I have Pro version Unity 4.3.0f4 with licence , whenever i trying to make Android Build ,following error message is showing

Error building Player: SystemException: ‘System.Net.Sockets’ are supported only with Unity Android Pro. Referenced from assembly ‘Assembly-CSharp’.

How to solve this problem ? Sorry for my english

That error means that you are trying to use Sockets, and this feature is available in the Android Pro plugin, but not in the free version. Please take a look at the comparison table:

You can buy this version in our store:

https://store.unity3d.com/