Did you check to have the money automatically withdrawn?
If there is a balance due, it can't do direct deposit. If your client wants to send in a check themselves then no need to change anything and check no for the auto withdraw from their account. Also double check if the account number is in the routing number field and vise versa. Routing numbers are 9.
If you go to the headers on each page (misc info, income, expenses) see what is red highlighted. Go into the page that has the red and look for the item that your program is showing the error in. There is a box either checked or not checked which is throwing that error.
I had same issue. Uncheck the electronic filing in Part VI and save, then see what other errors pop up. For me, I had Electronic Funds Withdrawal of Estimated Tax Smart Worksheet checked, once I unchecked that and re-check electronic filing in Part VI, the direct deposit error went away.