Please make sure you have your site set to play in English as otherwise things may not work properly. Please also make sure you're up to date with 4.07.4 - and if not please do upgrade.
If you have it playing in English, your hands are importing and you're up to date and still not seeing a HUD, please enable logging via Configure -> Options --> Logging enabled, restart PT4 and reproduce this problem. Then report it via our
support system with the log file - that will help us figure out what is going on here and get it fixed for you. You can find that file by clicking File --> Show User Data Folder in the main PT4 window - the file we need is the text file called PokerTracker4 that is in that folder.