Zwift crashes when signing up for training plan that was already started in the past

So I want to signup to a training plan that I had started and not finished in past. A dialog pops up asking if I want to restart or continue the plan. I can choose either, and the apps crashes.
I have tried with my Mac App, and also with the iOS app. Both of them are broken, and there is now way to proceed.

Sounds like you should contact support and have them look at the log files