So I've accidentally sent Spreadcoin to a Stratis address.
Yes, embarrassing.
I've tried importing the Stratis privkey for that address into the Spreadcoin wallet but I get the error message "Invalid private key (code -5)"
Any suggestions as to how I might go about recovering my lost Spreadcoin?
You can try to double spend the transaction or load the private key into a new wallet.
I haven't needed to try this before, so just give it a try and see if it works before we try something else, possibly creating a raw transaction.
dump your private key (use the public key from where you sent from) from your current wallet and copy + save it to a notepad file
copy your current wallet.dat file to somewhere safe
run spreadcoin which will create a new wallet.dat
import your saved private key. See if that loads your spreadcoins into the new wallet. It may not, but its worth a go.
Get in touch on slack or PM and we'll try to see if we can double spend your transaction.
I don't know if importing the private key will work.
Weren't Spreadcoin addresses different from most other coins to save space on the blockchain?