Per Image A - at the Floor combo box - when I backspace and remove the information per Image B, I get the above error message - 'You tried to assign the Null value to a variable that is not a variant data type'. Yet if I were to click on the combo box per Image C, I go to the top and can select the blank one.
How can I make Access understand when I backspace I'm trying to assign the blank value for now and will come back to assigning what it should be? Is my design wrong per Image D? Should I break the relationships so that a null value can be entered?
Please note I have the Access database sample below in a zip file...Room-Data.zip