The sheet again works OK with MC15 and Excel 2016.
Which version of Excel do you have installed? Which format has the file you embedded? I am not sure if MC14 can already handle the xlsx format introduced with Excel 2007.
As you use MC14 you may also ave a look at the release notes of newer Mathcad versions to see if its a known bug which was fixed in a later version. VladimirN posted those readmes here in the forum from time to time - here the one for the latest release M050 of MC15: https://community.ptc.com/sejnu66972/attachments/sejnu66972/PTCMathcad/176901/5/PTC%20Mathcad%2015.0%20M050%20Read%20This%20First.pdf
At a quick glance I spotted "Microsoft Excel 2007 Support" as a feature of MC15 F000 and also a fix in MC15 M010:
2007304: Fixes a problem with assigning data to a variable using an Excel component and an existing Excel 2007 file
Not sure of course if that relates to the problem you experience. Generally I see a lot of fixes in the list which in some way deal with Excel.