Latest grub update error message

[erfan]

Upgading to the latest grub resulted with an error message during my hidden grub timeout. Instead of the black screen show before, appears this message:

Error: Unable to determine partition UUID of boot device
[countdown number]

Why it is shown, what should I understand? At the end of the timeout it boots without visible issues and everything is working like before.

I had the previous grub.cfg, which had no error messages, so I am using it now, to not see the error message.

Should I be aware of this warning?