Just tested with fallout shelter and i had no problems, do this:
1)Unistall infinity.
-Use this tool - ICDV2.bat - (use default option,it will remove cache fast)
Or
-Do it manually way to delete corrupted cache:
%appdata%/Daring Development\Infinity folder and delete it
3)Try to attach and run Infinity, . First, launch the game via STEAM, then once the game level has been fully loaded -> open infinity and click run game.