If you are trying to use the tax planner to project TY2019 taxes, you will need to have prior year data.  The reason is that the planner relies a lot on what's on the prior year return as the baseline with a limited number of adjustments you could make for the projection.  If there's no prior year return data, there's no baseline data for these projections to run on.

Not ideal but that's how the planner is set up.