The QuickC editor can use only text files. You tried to load a file in an improper format: ■ binary file (.EXE, .COM, or .LIB files). ■ zero length file. ■ file with an extra carriage return at the end. Exit QuickC and use the CRLF utility to fix this file. ■ Pre-existing version of a .LST file or a corrupted .LST file. Generate a new listing file with QuickAssembler; the new file is guaranteed to have the correct format.