I made a startup USB flash drive for Ubuntu 15.04 using Startup Disk Creator as described here. I booted a computer using this flash drive and the boot process threw this error:
Missing parameter in configuration file. Keyword: path gfxboot.c32: not a COM32R image boot:
(This error happens even if the drive is created using UNetBootIn as described here. It happens with Ubuntu 14.10 too.)
help at the boot prompt. It will show a menu of options. Hit
Enter here and Ubuntu will boot up as it should have.