That happened last week also. The issue was corrected but now it's back. I'm able to modify my activities in the classic view on my PC which you access from the last icon on the action menu. I'm using that in the interim.
+1 I am having the same problem. The software sometimes uploads my activity and timestamps it with the wrong time zone (reported elsewhere in the forum). Typically, I just edit this but now it freezes when I try to edit the activity. Started doing this yesterday.
Garmin is having massive problems with software quality and delivering product experiences that live up to the hype and expectations they create. See my blog from yesterday with some additional thoughts.
