I am on the latest client 3.2.2 and following the cold storage instructions here:  http://docs.electrum.org/en/latest/coldstorage.html

**The only difference is that when creating the transaction in the watch-only wallet, the "save" button is greyed out and now there is an "export" button.  It creates unsigned.txn

When I load unsigned.txn in the offline, air gapped computer (also running the same client version), and click "sign" it gives me the following error:


Can Electrum no longer sign transactions offline?  Or am I doing something wrong?

THANKS