The modified date is usually displayed next to the file name in Windows Explorer when using the "Details" view. At this point you might just try renaming the programs.lst then start DimPro. If that does not work, a little more info would be nice. Such as, where did you put the files? Are you running DimPro 32bit, 64bit or both? What OS?
The default location for 64bit is
Multisamples - C:\Program Files\Cakewalk\Dimension Pro\Multisamples
Programs - C:\ProgramData\Cakewalk\Dimension Pro\Programs
and 32bit
Multisamples - C:\Program Files (x86)\Cakewalk\Dimension Pro\Multisamples
Programs - C:\ProgramData\Cakewalk\Dimension Pro\Programs