As Max says the Universal USB installer no longer seems to work for 0.30 beta 4 version.
It does totally makes sense. Universal USB installer it is designed to deal with isolinux based cdroms which are the most of them. I suppose they have not thought grub2 based live cds. So… What do to then?
As I have explained in the Rescatux wiki you should work with the iso (which happens to be an isolinux iso) which it is inside the iso you are downloading.
Another issue comes when using the official method. It does not work. Yes, it works. The usb boots and Super Grub2 Disk is fully functional but trying to boot any of the Rescatux options fails. As I explain in the issue the main reason for this for failing is that making Rescatux to boot from SG2D is more a workaround that a final solution. Either I improve the workaround (detect partition UUID when no label is found) or I implement the debian-live requested improvements for the grml fromiso patch which it is the final fix.
If you still want to use the official method for putting Rescatux into the USB what you should do… Yes, you have guessed… use the iso inside the iso as in the Universal USB installer case.
The nice thing about this is that I would have found this last problem myself if I had tested it… but I don’t try usb versions of Rescatux myself, just the cdrom version. I will have to improve that. 🙂