Invalid encoding error when importing private key in Bitcoin core

[tyz]

I tried to import private keys using the debug console in Bitcoin core client. I use the following command

importprivkey 5K... MyNewAddress

and I get the following error message

Invalid private key encoding (code -5)

Any idea what is wrong? A google search did not give me a hint.

[achow101]

Your private key is incorrect in some way. That is what that message means. You are probably missing a character somewhere, maybe forgot to copy one at the end.

[Velkro]

Your private key is incorrect in some way. That is what that message means. You are probably missing a character somewhere, maybe forgot to copy one at the end.

This one, or try including label so:
importprivkey yourPrivateKey "TheLabelThatYouWant"