Server issues, help is required

[Sheep in a suit]

To any with the knowledge:

I need help with entering servers--they always, no matter what server or modpack, upon clicking them, will display an error message(refer to images). I need help as I am unable to play any of the modpacks in multiplayer. 

Before you ask, I did restart the modpack/launcher/refresh the server.

Interestingly, when I loaded up Vanilla using the launcher the servers displayed the "Failed to login: Invalid Session", but when I used the servers without the launcher(i.e., using the Minecraft program and not the launcher), the servers were perfectly functional.   

   

Edited October 9, 2015 by Sheep in a suit
Add results from using vanilla servers with and without the launcher.