CorePure64 v6.4 mcookie not found

[TopNotch]

I'm getting this error on my installation of Corepure64:
/usr/bin/startx: line 12: mcookie: not found
failed in waitforx
I know there's another topic where this is solved, but what is said there is to cryptic for me to follow.
Could someone  please explain in detail what was done in that thread to solve the problem?

[gerald_clark]

Show your onboot.lst

[TopNotch]

Fixed "mcookie not found", but I still get "failed in waitforx".
Here's my onboot.lst:

aterm.tcz
fltk-1.3.tcz
flwm.tcz
freetype.tcz
glib2.tcz
harfbuzz.tcz
imlib2-bin.tcz
imlib2.tcz
libffi.tcz
libfontenc.tcz
libICE.tcz
libjpeg-turbo.tcz
libpng.tcz
libSM.tcz
libX11.tcz
libXau.tcz
libxcb.tcz
libXdmcp.tcz
libXext.tcz
libXfont.tcz
libXi.tcz
libXmu.tcz
libXpm.tcz
libXrandr.tcz
libXrender.tcz
libXt.tcz
pcre.tcz
wbar.tcz
Xfbdev.tcz
Xlibs.tcz
Xorg-fonts.tcz
Xprogs.tcz

[TopNotch]

Fixed "failed in waitforx". Added "vga=791" to extlinux.conf.
Thanks all.
Signing off. Mark it solved, or remove it entirely.

[gerald_clark]

Don't include all those libs in onboot.lst.  They will automatically pulled in as deps when needed,