protocol upgrade (20003->20012) not detected by latest binary (2.3.3)

+4 votes
when upgrading a blockchain (protocol), I run into the following problem:

1) The existing chain is 20003, the binary version of multichaind is 2.1.2
2) I follow the instruction from to upgrade to protocol 20012.
3) Everything worked.
4) When restarting multichaind 2.1.2 it detects the new version 20012. Other nodes also detect 20012.
getinfo says:
    [version] => 2.1.2
    [nodeversion] => 20102901
    [edition] => Community
    [protocolversion] => 20012

5) BUT: Moving to multichaind-latest (2.3.3) it stops with the following error:
MultiChain 2.3.3 Daemon (Community Edition, latest protocol 20013)
Starting up node...
ERROR: The protocol version (20003) for blockchain mc2a3 has been deprecated and was last supported in MultiChain 2.2 beta 3

What can be the problem?

asked Aug 3, 2023 by chris

1 Answer

0 votes
Protocol version 20003 was introduced in an alpha version of MultiChain 2.0, and we discovered a possible issue with it, so support for it was fully deprecated in the MultiChain 2.2 release. The last version to support this protocol was MultiChain 2.2 beta 3. Would you like us to make that download available for you?
answered Aug 6, 2023 by MultiChain
Thanks for the information.
The chain was already upgraded to 20012 (using 2.1.2)
The question is: Can I use the 2.2-beta-3 to "downgrade" it to some "useful protocol version" (which one?) and then use another binary version (which one?) to upgrade it to 20012 or 20013?
I'm afraid this won't help because you can't use a chain that was started on 20003 with the latest version of MultiChain, no matter what protocol it was upgraded to subsequently.
So I will leave it running on 2.1.2 as it has been since some years now.
Or is there any strong recommendation to move to 2.2-beta-3?
There's no strong recommendation either way. Please look at the version history in README.txt of version 2.3.3 to decide.