Support just helped me.

After you click the create EF file, look on the left side you will see WI highlighted.  You must double click on the WI icon(highlighted in green on my screen) , then a box pops up where you must manually enter the WI WH number.  I used copy and paste from my company screen.

I then tested the file on WI aok, and then I filed WI AOK

New procedure for 2019, EASYACCT does not automatically pick up the WI WH number from the company file, you must manually reenter it as listed above.