WARNING: Before using the coinb.in port, make sure you know how to ensure your workstation is safe and that you know how to use the page offline. To sign the TX, you’ll need your private key, and handling a private key always exposes it to risk. Do not even ask ElectrumG for your private key if you don’t know how to handle and use the key safely.
Having said all that, you can definitely use the coinb.in Verify page copy-paste your TX to confirm that the TX is properly formed. Doing this does not require your private key, so it’s less risky. It’s possible that there’s an error in your transaction that’s preventing ElectrumG from parsing it.
A small bug that can make some confusing:
The Wallet, Bitcoin Gold Wallet by Coinb.in say BTC in the balance, regardless of the coin selected in setting.
Were you also using Electrum portable for Bitcoin, or was that working because it was the full version?
And is it possible for you to provide a TX which reproduces this error so that it can go into an Issue on the Github? (Not your original, TX, of course, because of privacy concerns.)
Thanks.
(Ideally, you would open the Issue in Github with all the supporting details, but if you at least provide the necessary info here to reproduce the error, someone else can open the Issue. Either way, the Issue is the way to get the problem eventually fixed.)