You've changed your system and now spouse's line 236 is a required field. Neither of us will know this until we finish our taxes and then we enter this line at the end. If we can't get past that screen, how can we proceed? Why did you make a silly change like that? If required then put it at the end when people will actually have that information as part of the process.
You are only asked to enter line 236 for your spouse when you are not filing a coupled return. If you choose to file separate returns and you do not have the exact amount, the Canada Revenue Agency suggests that you do your best to enter an estimated amount.
If you are not doing a coupled/joint return- then TurboTax will ask you to enter the amount from line 236 of your spouse's return.
If you do not know their Net Income - This is what to do
If you don’t enter your spouse’s income (or an estimate), it’s important that you do not claim the "Spousal Amount".
Once both of your returns get assessed CRA will advise if you were able to claim the "Spousal Amount" and would make the changes for you.