Realms - Invalid Session when trying to log in.

Put the summary of the bug you're having here

What I expected to happen was...:
I tried to log into Minecraft Realms

What actually happened was...:
New launcher installed, received the message "Invalid Session" when clicking on Realms button.

Steps to Reproduce:
1. Click icon to load Minecraft
2. Click Realms button
3. Receive Invalid Session message.
4. Tried restarting, same results.