If the Bitcoin Chrome Applicaton displays: "Sending failed: unable to validate transaction" when you try to send a Bitcoin Gold amount it can mean:
- that you need to manually your Bitcoin Gold app in your Ledger Manager to v1.1.16 and add custom fees to your transaction : between 5 and 200 satoshis/byte works.
- that you do not use - and maybe did not download - the Bitcoin Gold application on your Ledger Nano S or Ledger Blue, from the Ledger Manager. Refer to this guide.
- or that you did use the Bitcoin Gold application, but something went wrong when synchronizing your information. If so, please reset the Bitcoin Chrome App : settings > tools > reset application data and try again