Glad to hear you have a fix. I am in Error 21 hell now with my wife's white Rad City 5 Plus step thru. I paid $60 for a new wiring harness that we connected but no luck. I contacted Rad support and now they sent me an email with an invoice for a new battery mount and controller @ $200 but when I went to order it was out of stock and when I complained they said it is a supply chain issue and they hope to have the part in January 2024! Almost laughable if not so disappointing.

I am not sure what to do next. The bike is a 2021 so out of warranty but it only had a 100 miles on it.