Possibly you omitted or misspelled the filename of a .4db input file (either in a READ command or following the -F command-line option), or you misspelled the filename or pathname of a .4gl source file in a VIEW command or on the command line.
If filename is spelled correctly and names a file that exists, then you might need to specify a complete pathname. You must specify the full pathname of a file when you refer to a .4db file that is not in the current directory, or to a .4gl source file that is not in the current directory or any directory that you specify with the -I command-line option.