Opened it in Excel on my laptop and verified that no leftover formulas in each worksheet by scrolling through each cell. Left cursor in cell A1 for each worksheet and the "optimization_parameters" worksheet on top.
Note that it has just now occurred to me that the issue might be with different versions of MS Excel doing something to the input files.
This input file was created with version Microsoft Excel 2013 (15.0.4885.1000) MSO (15.0.4903.1000) 64-bit, Part of Microsoft Office Professional Plus 2013.
Information found under File tab > Account (left menu bar) > About Excel button
File is 33,467 bytes; will not open or modify it during testing.
GRNmap version
I might as well use the draft v1.6 version; but since there is not a published release, I will have to use a download of the code from the Master branch; I will be careful to use the same set of files each time and not re-download in case there are changes to the repository. I have already shown that the executable and the code produce the same result on the same computer (back-to-back runs without restarting), so I'm not going to worry about that right now.