Basically, the data files used to be in .SLF format, and they were changed to .TXT format.  Go into the Bin folder as shown below:

C:
     \SellFolios_V4
          \YourProjectName
               \Bin

You will see several files with a .slf extension (if they are all in .txt format, you can skip this  entire step).  Right-click over each file, choose Rename, and change the .slf part to .txt , all lower-case.  If you get a prompt talking about security or stability of the file, just proceed.  For instance, if you see the following files:

mm.slf
mm_global.slf
mm_mktg.slf
mm_cont.slf
My_Projects.slf

... then change them all so that they have .txt file extensions:

mm.txt
mm_global.txt
mm_mktg.txt
mm_cont.txt
My_Projects.txt