Diagnosis
"Quarter Provided by ER" is unticked,but one of the radio button
"ER pay to rent to landlord" / "EE pay rent to landlord"/
"Reny key in manually" is ticked.

Procedure
please tick "None" if "Quarter Provided by ER" is unticked;
"Quarter Provided by ER" is ticked, please fill the related fields
("Nature", "% to Rent", "recovered from EE", "recovered from ER",
"ER pay to rent to landlord" / "EE pay rent to landlord"/
"Reny key in manually") for Rental.