Small Bug in a Workbook just been created.... Can you help me finding it??

I have created an Excel Workbook to calculate Food Costing for the catering trade. Unfortunately, I have a "small" bug that stop the process to complete. The freelancer coder is away on holiday and I need this repaired quickly. Can you help. I have a working file which I have attached. It should have enough information to help you understand the process it has already been loaded with ingredients to create recipes. To create a recipe we chose the Source of the next ingredient which could be either an INGREDIENT (will be chosen from the INGREDIENTLISTING sheet) or A RECIPE (will be chosedn from the RECIPELISTING Sheet). Once we know the Source we chose a CATEGORY of either INGREDIENT or RECIPE.... When the CATEGORY has been chosen we have a third column for the chosen INGREDIENT or RECIPE.... This is where the bug is... the combo should give us the appropriate listing but it is blank.... I have a file I am working on for a client which is already loaded with ingredients... this should help testing the issue. I have another Master Workbook which will need to also be amended once we understand the issue. I am quite sure it is not a huge problem :-) but I don;t have the expertise on this one. I understand Pivotal Table is being used for this workbook. I need this to help a client as soon as possible. Can you help?