I assume what this means is that
($(FilePath) & '*' & Str)
does not point to a valid path. Look in the document log to see what is being substituted in the Filelist().
From [$(FilePath)*$(Str)](txt, utf8, embedded labels, delimiter is ',', msq)
does not look correct. When your filelist works, you should be loading from $(File) like:
From [$(File)] (txt, utf8, embedded labels, delimiter is ',', msq)
Sorry for the delay in responding. You're correct. The 'Filelist' was not generating the correct path. It has to do with how I was specifying the path using variables and '*.' instead of just '*'. I moved the '.' inside of the variable where I specified the file extension, and it works great. I also removed the $() around the FilePath.
FOR EACH File IN FILELIST (FilePath & '*' & Str)