I was  looking around the Walkera website Last Sunday and  saw that the Devo 7 and 10 are not offered for sale.
Emailed them about getting a download of original Devo 10 firmware if they are not going to sell or support it.
Reply was  that I had no need to update any firmware as it was OK!    I  replied suggesting that  sometimes files get damaged and need replacing and as I assumed the tx was good for another few years... I was just  hoping to have a backup.  So far no  reply back.
I was wondering if this is why a lot of the Chinese stores are selling the 10 in Black and White and 7 - have Walkera dumped their old stock????
To a newbie  - it seems strange they are now selling a tx - 7e and 12 - with no means to upgrade or replace corrupted files - which I suppose could happen!
( Yes  I have  the files from the German fans site)