I'm sorry to hear about this issue you've been having. May I suggest that you open Smart Hub and then press FORWARD, 2, 8, 9, REVERSE in quick succession on your TV's remote. Follow the menu prompts and then try to access those programs again.
I can access SmartTV and use Pandora and the web browser without any issues. When I go into Samsung Apps, nothing works and I get an error that states a Network Error Occurred Error_Code_001. This is not a network or internet issue. It has to be an issue with Samsung Apps.