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).

Downgrade warning

Because release 0.10.0 and later makes use of headers-first synchronization and parallel block download (see further), the block files and databases are not backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:

• Blocks will be stored on disk out of order (in the order they are received, really), which makes it incompatible with some tools or other programs. Reindexing using earlier versions will also not work anymore as a result of this.

• The block index database will now hold headers for which no block is stored on disk, which earlier versions won’t support.

If you want to be able to downgrade smoothly, make a backup of your entire data directory. Without this your node will need start syncing (or importing from bootstrap.dat) anew afterwards. It is possible that the data from a completely synchronised 0.10 node may be usable in older versions as-is, but this is not supported and may break as soon as the older version attempts to reindex.

This does not affect wallet forward or backward compatibility.

Notable changes

This fixes a serious problem on Windows with data directories that have non-ASCII characters (https://github.com/bitcoin/bitcoin/issues/6078).

For other platforms there are no notable changes.

For the notable changes in 0.10, refer to the release notes at https://github.com/bitcoin/bitcoin/blob/v0.10.0/doc/release-notes.md

0.10.2 Change log

Detailed release notes follow. This overview includes changes that affect external behavior, not code moves, refactors or string updates.

Wallet:

• 824c011 fix boost::get usage with boost 1.58

Miscellaneous:

• da65606 Avoid crash on start in TestBlockValidity with gen=1.
• 424ae66 don’t imbue boost::filesystem::path with locale “C” on windows (fixes #6078)

Credits

Thanks to everyone who directly contributed to this release:

• Cory Fields
• Gregory Maxwell
• Jonas Schnelli
• Wladimir J. van der Laan

And all those who contributed additional code review and/or security research:

• dexX7
• Pieter Wuille
• vayvanne

As well as everyone that helped translating on Transifex.