Formula to show zero or blank cell based on multiple cell calculations

Hi,

I was after a formula that shows either 0 or leaves the cell blank if there is no data to calculate. For example (attached workbook) rows 4 - 11 have data (criterion) selected with data pre-filled in columns C and D. If a supplier is given a score of zero then their weighted score should be zero as per sample supplier B.

Rows 12 & 13 there is no criterion selected so no maximum score and weighting is pre-filled, therefore the entire row should stay blank and not show any zeros

No it doesnt work