I created a bootable USB with Rufus using Lubuntu 20.10 amd64 desktop iso image. I already have installed on my desktop Lubuntu 16.04.
I change the boot options in BIOS to boot from USB first and then i receive the following message:
GRUB loading.
Welcome to GRUB!
error: symbol ‘grub_calloc’ not found.
Entering rescue mode…
grub rescuse>
I try now creating another usb bootable stick using Unetbootin. I will let you know if it is working.
I have the same issue with UNetBootIn USB.
Since similar problems comes up every now and then here… I’d like to ask since I’m sure others are likely to ask: where did you get your ISO from? As in what website/webpage did you download from?
Should’ve been from here:
https://lubuntu.me/downloads/
After that, a lot of the council members here seem to recommend checking the integrity of the downloaded ISO file.
EDIT:
Incidentally, a lot of members here seem to also recommend not using Rufus. I guess to be definitive you could also try with Etcher instead.
I haven’t used UNetnoot id, but the point about first formating the stick to FAT32 is important (for all bootstick creators, not just UNetbootid).