ES450 will not update


#1

Hi I have 3 es450 in use - 2 have updated perfectly but one just will not update. I get the same message over and over again and need help to sort the problem. the es450 was is on the version before latest version so its fairly up to date but i had a warning saying there was a risk and need to update
keeps saying ‘could not find signature in the package’ at the applying stage of the update.
have also tried to update via the airvantage webpage several times but fails every time as well.

Help please! Thanks.