The session file contains paths and filenames for all the measurement files used in the session. Usually this error message means the measurement files have been moved to a different folder/directory or deleted, and thus can’t be found. If that isn’t the case for you, send your .fda file to info at eclipseaudio dot com and we’ll take a look. Are you on windows or mac? Are the files on the same drive, a different drive or a network share?