Try removing all commas from the numbers in the workout settings or change them to dots. I had the same problem - it appears when You click "edit workout" most numbers are presented in the form of "xx,xx" - but GC does not like the commas (it accepts dots) and replies with error on save. Good luck :)
I'm having the exact same problem - and can't create a workout no matter what type or what kind of settings. Rather annoying - especially since there's nowhere else to create workouts (neither on my Fenix 3 nor Garmin Connect mobile).
The error is: "The workout could not be saved because of a system error. Please try again later."
Exactly the same issue for me. And yes, it seems to be related to some comma vs dot representation - adding step without any changes/targets works fine
