user4334: Recently, my full node (Bitcoin Core 0.14.2) displays this for both HD and non-HD wallets:

Warning: Unknown block versions being mined! It's possible unknown rules are in effect

What does this mean?

user54721: I am not an expert at Bitcoin, but here is some of my research:
https://github.com/bitcoin/bips/blob/master/bip-0091.mediawiki
"While this bip (91) is active users should either upgrade to segsignal or wait for additional confirmations when accepting payments."
I guess this is why Bitcoin Core 0.14.2 displays the warning, on my end too.
More:
"BIP91: The SegWit Activation "Kludge" That Should Keep Bitcoin Whole"
https://bitcoinmagazine.com/articles/bip91-segwit-activation-kludge-should-keep-bitcoin-whole/

user208: Miners have started signalling for BIP 91, which sets bit 4 in version numbers. When BIP 91 activates, it will force miners to set bit 1 (which then indirectly will cause activation of BIP 141 SegWit).
No software release has implemented BIP 91, as a result, it warns because it sees an unknown feature rollout with significant support from miners.

4334: <p>Recently, my full node (Bitcoin Core 0.14.2) displays this for both HD and non-HD wallets:</p>

<blockquote>
  <p>Warning: Unknown block versions being mined! It's possible unknown rules are in effect</p>
</blockquote>

<p>What does this mean?</p>
 54721: <p>I am not an expert at Bitcoin, but here is some of my research:</p>

<p><a href="https://github.com/bitcoin/bips/blob/master/bip-0091.mediawiki" rel="nofollow noreferrer">https://github.com/bitcoin/bips/blob/master/bip-0091.mediawiki</a></p>

<p>"While this bip (91) is active users should either upgrade to segsignal or wait for additional confirmations when accepting payments."</p>

<p>I guess this is why Bitcoin Core 0.14.2 displays the warning, on my end too.</p>

<p>More:
"BIP91: The SegWit Activation "Kludge" That Should Keep Bitcoin Whole"
<a href="https://bitcoinmagazine.com/articles/bip91-segwit-activation-kludge-should-keep-bitcoin-whole/" rel="nofollow noreferrer">https://bitcoinmagazine.com/articles/bip91-segwit-activation-kludge-should-keep-bitcoin-whole/</a></p>
 208: <p>Miners have started signalling for BIP 91, which sets bit 4 in version numbers. When BIP 91 activates, it will force miners to set bit 1 (which then indirectly will cause activation of BIP 141 SegWit).</p>

<p>No software release has implemented BIP 91, as a result, it warns because it sees an unknown feature rollout with significant support from miners.</p>
