Yes that was the problem.
I got confused between 2.0.1 and 2.1.0 after downloading the trunk source.
From: Robert Coli [mailto:email@example.com]
Sent: 25 September 2013 18:10
Subject: Re: 1.2.10 -> 2.0.1 migration issue
On Wed, Sep 25, 2013 at 6:05 AM, Christopher Wirt <firstname.lastname@example.org> wrote:
Should also say. I have managed to move one node from 1.2.10 to 2.0.0. I’m seeing this error on the machine I tried to migrate earlier to 2.0.1
I'm confused... for the record :
1) you tried to upgrade from 1.2.10 to 2.0.1
2) the NEWS.txt snippet you posted refers to upgrading from versions below 2.0 to 2.1
3) 2.0.1 is 2.0, not 2.1
Therefore the problem is actually https://issues.apache.org/jira/browse/CASSANDRA-6093 ?