My files were programs ending in .sit that caused me problems. Try this. Drag file to desktop. With Stuffit Deluxe go to translate menu, encode binhex and save to another folder. You can then open them.I have only tried encode binhex-others might work. You can then open the file.
John p

Had this same problem. It seems to have disappeared as of v1.8.

However, some files, specifically .sit files still read as Limewire files in my Shared window. Dropping these onto Stuffit Expander (NOT regular Stuffit Deluxe) seems to extract them just fine, and thereafter, the archives show w/normal Stuffit icon.

drag the downloaded file onto stuffit expander, it will then open and appear as a stffit document. Then double click and expander will open it fully.