I have a watching wallet on Windows 10 on electrum 2.7.11. I have saved a transaction and saved it to my USB key and transferred it to my offline PC which is never connected to the internet. Ever.



I load electrum 2.7.9 on there and load the transaction from USB key. All good so far. When I click Sign, I get a message saying please wait, signing transaction... and then Error. Server did not answer.



Well, obviously because it's offline. How do I sign a saved transaction?



Did you follow this guide to the letter http://docs.electrum.org/en/latest/coldstorage.html