When using a reader to a very long path and filename. Or to files within a zip-file with very long paths and filenames FME usually gives "File not found"-error in the logfile. Give a better explanation to the user when the path is very long so the user can just move the files to a folder with less letters.
Or when reading a file with long name (more than 260 characters - mspoweruser.com/ntfs-260-character-windows-10/ ) try to move the file to FME-temp folder and then read it from there.
Since some project-disks are long by default it is not possible always to shorten the path where the original data lies