On October 7th Polar made an unexpected change to the Polar Flow service which necessitates an update to the RunGap app itself.
In just a few hours an updated app was prepared and it is currently awaiting approval by Apple before it can be released in the App Store. Unfortunately this may take anywhere from a couple of days to a week or longer.
In the mean time here is a list of steps that you can use manually import your new workouts to RunGap on your iPhone or iPad:
1) Open safari on your device and go to the flow.polar.com website.
2) Log in with your email and password:
3) select "FEED" from the upper left menu:
4) Scroll to the workout that you want to transfer and tap on the graph marked with a red circle below:
5) Scroll to the bottom and tap the "Export session" button:
6) Tap on "Session (TCX)"
Choose "Open in RunGap..." or "Open in..." and then RunGap to send the data directly to RunGap:
That's it :)