2016 TT H&B update 12/16/16: Sched C Part 1 Line 1a form-view data entry broken - cannot edit or delete a prior value. Workaround is change this value via Step-by-step.

In form-view, program does not respond to right-click menu choices in this field of Add Supporting Details or Data Source. The un-editable field behavior is typical of fields that have a Data Source but none is offered.  Either the un-editable behavior is intended and the Data Source function was not completed or the un-editable behavior property itself is the programming error.  The discovered workaround adds a level of confusion as to the intended editing behavior of this field.