Same issue, date/time fix didn’t help as my time/date is correct. This is some serious BS, not even a not from dev’s they are aware of this, I had gem tab access first day of 3 day early launch. Since then nothing but blank tabs.
UPDATE: Tried a few times to launch as admin gw2.exe and no go. Then I set the properties on the desktop shortcut to “run this program as admin” and launched it asks to confirm you want to launch as admin hit yes and poof I get in game and can see TP all tabs.