Bitcoin Core version 0.9.2.1 is not available for security reasons:
https://bitcoin.org/bin/0.9.2.1/
This is a new minor version release, bringing mostly bug fixes and some minor
improvements. OpenSSL has been updated because of a security issue (CVE-2014-0224).
Upgrading to this release is recommended.
Please report bugs using the issue tracker at github:
https://github.com/bitcoin/bitcoin/issues
Upgrading and downgrading
How to Upgrade
If you are running an older version, shut it down. Wait until it has completely
shut down (which might take a few minutes for older versions), then run the
installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or
bitcoind/bitcoin-qt (on Linux).
If you are upgrading from version 0.7.2 or earlier, the first time you run
0.9.2.1 your blockchain files will be re-indexed, which will take anywhere from
30 minutes to several hours, depending on the speed of your machine.
Downgrading warnings
The ‘chainstate’ for this release is not always compatible with previous
releases, so if you run 0.9.x and then decide to switch back to a
0.8.x release you might get a blockchain validation error when starting the
old release (due to ‘pruned outputs’ being omitted from the index of
unspent transaction outputs).
Running the old release with the -reindex option will rebuild the chainstate
data structures and correct the problem.
Also, the first time you run a 0.8.x release on a 0.9 wallet it will rescan
the blockchain for missing spent coins, which will take a long time (tens
of minutes on a typical machine).
Important changes
Gitian OSX build
The deterministic build system that was already used for Windows and Linux
builds is now used for OSX as well. Although the resulting executables have
been tested quite a bit, there could be possible regressions. Be sure to report
these on the Github bug tracker mentioned above.
Compatibility of Linux build
For Linux we now build against Qt 4.6, and filter the symbols for libstdc++ and glibc.
This brings back compatibility with
- Debian 6+ / Tails
- Ubuntu 10.04
- CentOS 6.5