On Monday 2nd of January there have been some problems with the zwift server, so the activity couldnt get uploaded. Ive found it in my PC and I achieved to make an upload to strava, the ride-data is completly. But how can I save the ride to zwift? Actually I´m doing the 6 Week FTP Builder Beginner, but Week 6 Day 1 is “lost in space”. I`m a newbie here at zwift, so please help me 
Thx
Zwift Team,
I have a similar case - I did a workout yesterday (April 1st) and it doesn’t show up as an activity, except that my all time Stats add up, including the workout.
Could it be that the workout activity was not properly saved, although while performing this workout these were real-time added in the grand total?
Best, Jeroen