Must update to 0.1.6.3, more details below:

@everyone Binaries for 0.1.6.3 are up. rolls back the hardfork height so it will not take place at previously scheduled. everything else works fine. so ledger will still work, you'll get a bit of a boost on your mining and sync speed, just the hardfork won't happen just yet. a potential problem has been found in the PoW algorithm and it needs to be investigated. could end up being nothing. but if it is something, it's better to know that a few days before the fork rather than a few days after.

However. there is a but to this story. the binaries are now going to have a minimum supported version of 0.1.6.3. this is to prevent people who maybe running 0.1.6.2 at the fork height from disrupting the network. the seed nodes are currently configured to accept connections from old nodes, but these binaries will not. so you may notice a lack of connections until more people update. you can override this by using the --min-version flag like
./nervad --min-version 0.1.5.6 if you have trouble getting connections. but it is 100% not advised to run it like this at around the time of the (now defunct) hardfork and it is better to just see how you go with connections before using this option.