When I input your numbers, the spreadsheet indicates the following : "Error - Insufficient funds for owning".
Meaning that you also need to update the values in the "Income and Savings" section. For example, if you update cell H29 to $200,000, you should get rid of the error.
If you could unprotect the sheets, it would likely make your life easier and help you fully understand what's going on in there. Good luck with that spreadsheet!