Maybe you have a pending BTC transaction on your old wallet but the Kucoin support team is the only way to learn the efficient solution for this error.
Nah, that wasn't it--and I have no idea what the problem was, but I just tried it again and I was able to generate a bitcoin deposit address.
But as far as Dash goes, I just get this:
as well as for Neblio, which is just a random coin that I tried to see if I could get a deposit address. I'm not sure why Kucoin has got multiple coin wallets in maintenance mode, though I'm assuming it has to do with the investigation of the hack....or something related to that.
Well anyway, I'm glad they're still in business and I do hope they don't go under because of the hack. It isn't as though the amount stolen was small. Got my answer, and I thank everyone who tried to help. Locking thread now.