Almost made it through the upgrade.

gistfile1.txt

[private-chef-upgrade] -        Running Command: rm -f /var/log/opscode/opscode-chef-mover/parsed_console.log with options {}
[private-chef-upgrade] -        Running Command: private-chef-ctl restart opscode-chef-mover with options {}
ok: run: opscode-chef-mover: (pid 12145) 0s
[private-chef-upgrade] -        Running Command: /opt/opscode/embedded/bin/escript /opt/opscode/embedded/service/opscode-chef-mover/scripts/migrate with options {}
Successfully Migrated: 

SO MANY ORGANIZATION NAMES.... 

      Failed to Migrate: 
      
      A WHOlE BUNCH MORE ORGANIZATION NAMES..
      
          Not Attempted: none

Errors or warnings occurred.

/opt/opscode/embedded/service/partybus/lib/partybus/dsl_runner.rb:14:in `instance_eval': Partybus failed to execute command '/opt/opscode/embedded/bin/escript /opt/opscode/embedded/service/opscode-chef-mover/scripts/migrate' exitstatus: 1 (RuntimeError)
        from /opt/opscode/embedded/service/partybus/lib/partybus/migration_api/v1.rb:69:in `run_command'
        from (eval):53:in `block in run'
        from /opt/opscode/embedded/service/partybus/lib/partybus/migration_api/v1.rb:13:in `instance_eval'
        from /opt/opscode/embedded/service/partybus/lib/partybus/migration_api/v1.rb:13:in `initialize'
        from /opt/opscode/embedded/service/partybus/lib/partybus/dsl_runner.rb:25:in `new'
        from /opt/opscode/embedded/service/partybus/lib/partybus/dsl_runner.rb:25:in `define_upgrade'
        from (eval):2:in `run'
        from /opt/opscode/embedded/service/partybus/lib/partybus/dsl_runner.rb:14:in `instance_eval'
        from /opt/opscode/embedded/service/partybus/lib/partybus/dsl_runner.rb:14:in `run'
        from /opt/opscode/embedded/service/partybus/lib/partybus/migrations.rb:41:in `run_migration'
        from ./bin/partybus:62:in `block in do_upgrade'
        from ./bin/partybus:58:in `each'
        from ./bin/partybus:58:in `do_upgrade'
        from ./bin/partybus:79:in `block in <main>'
        from ./bin/partybus:70:in `open'
        from ./bin/partybus:70:in `<main>'

Hey, we had an identical error where it would fail on migrating from 1.17 to 1.18 and we were able to get through it by running sudo chef-server-ctl stop then sudo chef-server-ctl upgrade. There was also a considerable period of time between when it errored out and when we stopped the services and retried the upgrade. Honestly not certain about what caused the issue or what precisely fixed it.

EDIT: We were moving from chef-server 11.18 enterprise to 12.1 enterprise