Then the private key you are trying to sweep is not for address: 1Hefr1NLzABVZhK9Kh7XSB55xRFtK5ex6e
Just confirm that your private key starts with a "5" or a "K" or an "L"??... DO NOT post your private key here!
It's possible that this might be a compressed/uncompressed key issue... Very unlikely, but you never know... I'd suggest that you try using an offline copy of www.bitaddress.org and on the "details" tab, pasting in your private key and seeing what addresses it actually generates.
If you see the "1Hefr" address shown, then double check that the associated private key in WIF format is the one you're actually trying to sweep
Just confirm that your private key starts with a "5" or a "K" or an "L"??... DO NOT post your private key here!
It's possible that this might be a compressed/uncompressed key issue... Very unlikely, but you never know... I'd suggest that you try using an offline copy of www.bitaddress.org and on the "details" tab, pasting in your private key and seeing what addresses it actually generates.
If you see the "1Hefr" address shown, then double check that the associated private key in WIF format is the one you're actually trying to sweep
But, but... I literally copy the private key from that address (in electrum, right click on address --> private key --> enter my pw --> copy the key and enter it in Sweep).
It does mention that the inputs need to be confirmed but for as far as I understand it's been confirmed.
Can confirm that my private key starts with one of those you mention there. I'm going to try the bitaddress option soon and will report back.
I don't know what a compressed/uncompressed key issue is so I can't comment on that...
EDIT: bitaddress returns 1Hefr1NLzABVZhK9Kh7XSB55xRFtK5ex6e as the generated key which is the same as shows up in electrum.