starts with xprv and when entered on the Import Bitcoin addresses or private keys screen on Electrum the "Next" button is grayed out.
the links from bitpay explaining how to get the private key are unnecessary as the app has a simple button to export the private key so there is no need to do that long drawn out process - that being said - I did it yesterday anyways and it just provided me the same private key that the app does. Again, I believe I stated this above.
If it starts with xprv, then that's basically your wallet's master private-key. You need to select Standard Wallet -> Use a master key; then paste it in there and click Next. That should work.
ok this allowed me to enter my private key but it shows zero balance which is incorrect. It provided a receiving btc address that is not the one I use. I tried to do a sweep and it wont take the master key there though.