I own a stock and alpaca will not let me sell it

I own a stock and alpaca will not let me sell it neither by console not by API.

Console error:
Order Not Created asset KSU is not tradable

API error:
alpaca_trade_api.rest.APIError(‘asset KSU is not tradable’)

Follow up: This was due to a merger.

What happened? Did it get bought out or switched to a new symbol?