No comp in file Core52840/FileHeader

$ lua53.exe ad2kicad.lua Core52840.PcbLib
No comp in file Core52840/FileHeader
lua53.exe: .\ad_lib.lua:924: attempt to get length of a nil value (local 'compList')
stack traceback:
        .\ad_lib.lua:924: in function 'parse_schlib'
        .\ad_lib.lua:945: in function 'convert_schlib'
        ad2kicad.lua:95: in main chunk
        [C]: in ?