Side note to add to Throgh's reply...

It is advisable to always use the latest .iso to avoid potential problems.

That being said, which guide were you using?

If you can log into root and put in a usb thumb drive and mount it, you can solve your problems extremely easily.

However, if you cannot boot the system, do not despair!  you can still get the info if you have a live iso!

you just need to do a few things, although it depends on if you have encrypted install or regular,

if it is encrypted with the libreboot way,

cryptsetup luksOpen /dev/sdXY lvm

mount /dev/matrix/rootvol /mnt

genfstab -U -p /mnt >> /mnt/etc/fstab

arch-chroot /mnt

make sure you mount your usb thumb drive

Then you use copy everything onto the usb thumb drive. 

Done this many times, due to my own knuckleheaded ways...

But if it is a different way, I recommend you tell us, so we can help.

Small note btw,  if you installed 0.4, you will need pmount

for mounting the usb storage,

and then do this:

pmount /dev/your_drive_With_your_files

Then you mount  the usb drive

then copy it to your usb drive.

I hope this advice helps you alot!

You may want to print this out, or use a 2nd computer to look at, to do what I am suggesting.

Tell me if it works out!  But just to be clear, this is probably your best shot right now.  As annoying as that may be.

Although, I think you are capable of this.

You were the one who came up with that helpful newbies Full Disk Encryption guide.

Btw side note, your guide and the libreboot/Official guide had one problem that can easily be fixed.  I talk about it...

here:

https://forums.hyperbola.info/viewtopic … 4046#p4046 

One last thing btw, if its your guide, you need to do it somewhat differently...

Aka, I think you need to mount everything you mounted when you were installing it

Anywho, peace and hope you succeed!