Bitcoin Core - Unable to Send

[BrianH]

What is going on? Why can't I send? This is the error I am receiving from Bitcoin Core when I try to send bitcoins:
"Can't generate a change address key. No keys in the internal keypool and can't generate any keys."

https://postimg.cc/k2c76MRG

[ranochigo]

Go to Windows>Console and type the following, skip the first one if your wallet is unencrypted, replacing the password accordingly:

Code:

walletpassphrase PASSWORD 500

And

Code:

keypoolrefill

Try again if it works. If not, what does the console say?

[NeuroticFish]

I would start by reading this: https://github.com/bitcoin/bitcoin/issues/16091
One proposal was a downgrade back to 0.17.1; maybe you can try that (of course, backup your wallet first).

[BrianH]

Thanks for the help, all.

Go to Windows>Console and type the following, skip the first one if your wallet is unencrypted, replacing the password accordingly:

Code:

walletpassphrase PASSWORD 500

And

Code:

keypoolrefill

Try again if it works. If not, what does the console say?

Console says null.

NeuroticFish's link looks like it will fix the issue. I recently encrypted an old wallet from 2011. I did not upgrade it to HD, as far as I know. Wish I could return to the old unencrypted wallet...

Edit: I downgraded Bitcoin core to v17.1 and send works again.

However, my transaction is going unconfirmed. It looks like the client is mining a pre-fork chain. "Warning: Unknown block versions being mined! It's possible unknown rules are in effect"