Trouble with Replace-By-Fee Option

[MJS_gold]

I sent my last transaction with a low fee and the "replace by fee" option enabled, just to give it a try. Now when I right click the unconfirmed tx in the History tab and select "Increase fee", it gives me the option to set a higher fee. But when I try to sign the new transaction, I get an error message that looks like this: http://imgur.com/a/O1vyD

Should this feature work when using Electrum with a hardware wallet? I did not click the "Final" checkbox after setting the higher fee; is that required? I'd welcome any help!

EDIT:  Might the error have anything to do with the original transaction only having one output?

[Jhanzo]

I sent my last transaction with a low fee and the "replace by fee" option enabled, just to give it a try. Now when I right click the unconfirmed tx in the History tab and select "Increase fee", it gives me the option to set a higher fee. But when I try to sign the new transaction, I get an error message that looks like this: http://imgur.com/a/O1vyD

Should this feature work when using Electrum with a hardware wallet? I did not click the "Final" checkbox after setting the higher fee; is that required? I'd welcome any help!

EDIT:  Might the error have anything to do with the original transaction only having one output?

Checking the "Final" checkbox will make the transaction non-replaceable.  Having only one output shouldn't be a problem.

Try signing the transaction using the command line or another wallet.  For the command line check how at http://docs.electrum.org/en/latest/coldstorage_cmdline.html

[MJS_gold]

Try signing the transaction using the command line or another wallet.  For the command line check how at http://docs.electrum.org/en/latest/coldstorage_cmdline.html

Those instructions are a bit over my head.  

Are you sure it is possible to sign the transaction using the command line when the private keys are stored in a Ledger Nano?

Edit:  When I tried entering "cat unsigned.txn | electrum signtransaction - > signed.txn" in the Windows Command Prompt window, it did not recognize "cat" as a command.  Is there some other place where the command should be entered?

[MJS_gold]

I discovered another place to try entering the commands shown on the Electrum support page:  the "Console" window of the Electrum program.   So I saved the unsigned tx file in the same folder in which the Electrum program was installed and I copied-and-pasted the "cat unsigned.txn | electrum signtransaction - > signed.txn" command into the console window.   It responded "SyntaxError: invalid syntax."   

Was that the right place to enter the command?

[Jhanzo]

Actually never mind about the command line.  Apparently it's not available for windows.
Just enter this in the python console: signtransaction('unsignedrawtransaction')

You'll have to import the keys to another wallet however.  Supposedly you can use external keys by using signtransaction('unsignedrawtransaction', 'privkey=xxx') but for the life of me I can't get that to work.

[MJS_gold]

Thanks.  I'm too paranoid about exposing my private keys to hackers to start messing around with stuff I don't fully understand.

Has anyone been able to use Electrum's "replace by fee" feature with a Ledger Nano?