Segwit address creation I'm unable to create a segwit address in Bitcoin Core 15.0.1 64-bit Windows
I have tried multiple times but keep getting the same error.  The following is the output from the console

$ getnewaddress
1KxN5zBSMqCiMfaXpbgpbDipo3fdrWmWnF
$ addwitnessaddress 1KxN5zBSMqCiMfaXpbgpbDipo3fdrWmWnF
Public key or redeemscript not known to wallet, or the key is uncompressed (code -4)


I have also tried changing my encryption password but it did not help.  I do not want to create a whole new wallet.  What else can I do?  Thanks
Your wallet is probably old enough that uncompressed public keys are used instead of compressed public keys. Segwit only works with compressed public keys so you cannot currently use segwit with your addresses.

However you can upgrade your wallet to using compressed keys. To do so, first start Bitcoin Core with the -upgradewallet option. That will upgrade your wallet to use compressed keys by default. Then you will need to call getnewaddress ~1000 times in order to get to addresses using compressed public keys keys. I don't believe that there is a way to regenerate the keypool without emptying it by requesting all of the addresses from the keypool.