@Dan Ritter 
> Not unless you care about Secure Boot. (You probably don't.)
 
yea i already disabled the secure boot option and the error didn't go away.
@Roberto C. Sánchez
> Did you read the wiki page link that was in the log?
 
actually i managed to update the 
atheros firmware to the 
buster-backports version which i suppose was the latest version as the 
packages.debian.org states but the error still persists.
cheers