Don't have a smart tv myself but found the following on the web which may be of benefit to you.
"The answer is to RESET the Smart Hub.
This is not the same as resettiing the TV. In simple terms, you have two sets of software inside your smart TV; one looks after the TV side of things, and the other looks after the smart Apps side. Most people when they get this problem try resetting their TV, but they don't reset the Smart Hub -- so the problem doesn't go away.
Basically when you reset the Smart Hub, you are getting the Hub and your router to shake hands again. You will have to reinput your router password if you are running a secure network. People have complained in this forum that they can't reset the connection fully, from scratch, between their TV (really the Hub) and their router. This is how you do it....
In the Smart Hub, select "Tools" (look right down to the bottom edge of the screen, towards the right). In the "Tools" menu select "Settings". In the "Settings" menu select "Reset". The unit will then ask you for the password or PIN that you may have created when you orginally set up your TV. If you didn't enter one at that time, the Samsung default is 0000 (zero, zero, zero zero).
The unit will then reset itself - and if there is a fault in the handshaking between the unit and your router, it will reset the connection with the router (asking for the network password if there is one). You will have to accept a couple of "Agreement" pages (which is what you did when you orginally set up the device). >>> You are basically just doing it all again.
Be patient while the Smart Hub will downloads and reinstals the smart Apps. Then you are good to go."
Be aware of the last paragraph above as it might affect what you have installed
This is where the info came from