Our team is still on this issue.
We are continuing to work on the release of the fix. The current ETA is in 40 minutes.
As a quick fix, the orders can still be placed if the setting “Ask for a billing address during checkout” is disabled. To disable it go to your "Control Panel > Settings > Cart & Checkout" page at https://my.ecwid.com/#cart
and toggle the switch next to it.
We are really sorry about the delay.