When using Scancat-Lite-Plus (SCL) on Windows 7 you may experience an error when trying to save an RSD file.
USUALLY no matter how many times you click in "Save", it just sits there and won't save it.

If you look closely, you will see the filename looks something like this
    sample.rsd.*txt

However trying to erase the *txt
and saving the file as "sample.rsd" will then produce the error
    "The Filename is not valid"

What is REALLY happening is Windows does not recognize the RSD file extension type,

This could apply to OTHER Scancat Extensions such as "NFF" or "DAT" and etc.

The FIX is really simple.
You need to add the ''RSD'' extension to the accepted list in Windows.

http://www.sevenforums.com/tutorials/18212-index-add-remove-file-types.html

If you don't know how to do this,
Use the above link to view step by step instructions
   on how to add RSD to the "list" <ggg>