Chef 12 upgrade failed

gistfile1.txt

Chef 12 server started
Writing knife-ec-backup config to /tmp/knife-ec-backup-config.rb
Uploading transformed open source Chef 11 server data to Chef 12 server
Restoring users
Updating user record for admin
...
Restoring organization[<org here>]
Restoring org admin data
Restoring the rest of the org
Updated /clients/chef-webui.json
Updated /clients/dossier.json
Updated /cookbooks/berkshelf-0.3.1
Created /cookbooks/berkshelf-cookbook-0.3.1
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Field 'metadata.maintainer' invalid"]}
Updated /cookbooks/tar-0.3.1
Created /cookbooks/tar-cookbook-0.3.1
ERROR: /cookbooks failed to write: HTTP error writing: 400 "Bad Request" cause: {"error":["Invalid value '[]' for metadata.platforms"]}
ERROR: Chef::Exceptions::MetadataNotValid: Cookbook loaded at path(s) [/tmp/d20150224-6611-tbt7wl/install_from] has invalid metadata: The `name' attribute is required in cookbook metadata
Failed uploading transformed data to the Chef 12 server