Please check that you have the correct player name selected in the Player List in the sidebar on the left.
(If you want to link your PokerStars and WPN names together so that you see combined stats see this Tutorial: Aliases
Also check that you are in the correct cash ($) or tournament (T) section.
After that make sure that you do not have any filters enabled. Anything in blue in the sidebar is filtered, so clear all of those.
If you see stats but not hands then you may have the 'Show Marked Hands Only' option enabled above the hands report, or one or more tags selected in the dropdown list next to it, so also clear those.
If you still can't see your stats please attach a screenshot
of the full PT4 window either or privately in a Support Ticket
so that we can take a look for you.