The App might not open for a few reasons. If they persist please contact support.
1) If you are experiencing an issue where the Spitfire Audio App will not open, this could be because a file called the lm.conf needs deleting prior to launching.
Depending on your OS, here are the locations for lm.conf:
Mac OS: User/Music/Spitfire Audio/Settings/lm.conf
Windows: Roaming/Application Data/Spitfire Audio/lm.conf
On Windows, you may need to search %APPDATA% in order to find this file path as it can be a hidden folder.
2) If you are connected to the internet, but the app displays the image below, disconnect your firewall.
If this issue persists after making changes to the firewall/antivirus software, please contact support. It is likely that we are experiencing server difficulties.