Have you encountered the below error when trying to cancel a Sales Order?

"Error: The system cannot determine the default tax rate for tax CITY and tax status STANDARD. Please contact your tax manager either to specify a default tax rate code for this tax status and date &DATE or to define appropriate rate determination rules. (TAX_DET_DATE=20-DEC-19)"

This is an extremely frustrating feature in EBS as the documentation does not give any reasonable clue  why this is happening and besides, what do we care about the tax rate when the order is to be cancelled anyway?

I tried to find where the TAX_DET_DATE comes from and it seemed like this should be the TAX_DATE from OE_ORDER_LINES_ALL.

Well, it is not.

It is PROMISE_DATE from OE_ORDER_LINES_ALL.

This is beyond silly, but when I pointed this out to DEV they just shrugged and said that works as designed. 

Anyway, change the Promise Date on your order lines to be today any you will be able to cancel the order.