e-Sword 8.x Module Download:
Download Catholic vs Protestant Bible Study.top.exe

This file does not open in e-sword.  It is not a .topx file it is a .top file

Actually, eSword can open it. Here is the procedure:

Start e-Sword, go to the Topic Notes Editor window, hit <ctrl> and at the same time right click on the main window pane and select "Open...".  In the lower left of the Open File dialog box where you see "Topic Notes Files (.topx)",  click the drop down button, and select, "Old Topic Notes Files (.top)".  Use the dialog box to navigate to the folder where you have  the TOP file (usually it will be in the same folder where the program file was installed), select it and click "Open". 

While here I might as well say I was disappointed in this module. I found it to be almost completely devoid of actual comparisons between Catholic scriptures and Protestant Bibles. It was basically someone's promo piece for the Catholic Church.

I should add that once you have used this procedure to open a TOP file, you do not need to repeat it. It will appear in the sSword Reference Library unless the module is uninstalled.