Simulating probability distributions in Excel

In the attached spreadsheet, we attempt to fit (i) a multivariate t distribution, and (ii) a t copula, to a series of simulated data. The fitting of the multivariate t distribution seems correct, as the degrees of freedom max out at 5 (which is what you would expect given the setup), but there is a problem with the fitting of the t copula because there is no maximum for the degrees of freedom here. The task is to look through this spreadsheet (it should be relatively straightforward), and to identify where the problem is and to fix it. In placing bids, please indicate whether you understand the spreadsheet and how much experience you have of simulating distributions in this way.