A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
After being stuck with this problem for well over a year, I have figured out that the problem may very well lie in a hidden PERSONAL.XLSB workbook.
I followed the "clean XLSTART" folder solution called out several times before in this thread and was able to solve the issue.
I believe that what Excel is trying to do when opening the Blank Excel Window is to try opening a hidden PERSONAL.XLSB workbook. If you go to "View --> Unhide" you will find the PERSONAL.XLSB file becoming unhidden.
By moving the PERSONAL.XLSB folder to some place else and cleaning up the XLSTART folder, the problem is now fixed.