Unable to (re)configure recently version (7.10.1&4)

Hi, there.

I’m using gitlab-ce in Ubuntu 14.04.x(omnibus package).
When using ‘gitlab-ctl reconfigure’ or upgrading version, failed to reconfigure with chef.
However “gitlab-ctl restart” success, and is accessiable after reconfigure with error.
Is this safe?

output:

Chef Client failed. 8 resources updated in 17.389865273 seconds
[2015-05-13T05:43:36+09:00] ERROR: Invalid UTF-8 string: cannot encode to UTF-8
[2015-05-13T05:43:36+09:00] FATAL: Chef::Exceptions::ChildConvergeError: Chef run process exited unsuccessfully (exit code 1)

chef’s stacktrace below:

Generated at 2015-05-13 05:43:36 +0900
Chef::Exceptions::JSON::EncodeError: Invalid UTF-8 string: cannot encode to UTF-8
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/json_compat.rb:105:in `rescue in to_json'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/json_compat.rb:102:in `to_json'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http/json_input.rb:34:in `handle_request'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:222:in `block in apply_request_middleware'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:220:in `each'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:220:in `inject'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:220:in `apply_request_middleware'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:141:in `request'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/http.rb:118:in `put'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/node.rb:524:in `save'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/client.rb:287:in `save_updated_node'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/client.rb:433:in `do_run'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/client.rb:213:in `block in run'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/client.rb:207:in `fork'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/client.rb:207:in `run'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/application.rb:236:in `run_chef_client'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/application/client.rb:338:in `block in run_application'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/application/client.rb:327:in `loop'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/application/client.rb:327:in `run_application'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/lib/chef/application.rb:55:in `run'
/opt/gitlab/embedded/lib/ruby/gems/2.1.0/gems/chef-11.18.0/bin/chef-client:26:in `<top (required)>'
/opt/gitlab/embedded/bin/chef-client:23:in `load'
/opt/gitlab/embedded/bin/chef-client:23:in `<main>'

current gitlab.rb;

external_url "https://example.jp:2443/"
unicorn['port'] = 8081

# SMTP configuration
gitlab_rails['smtp_enable'] = true
gitlab_rails['smtp_address'] = "example.jp"
gitlab_rails['smtp_port'] = 25
gitlab_rails['smtp_user'] = "gitlab"
gitlab_rails['smtp_domain'] = "example.jp"

gitlab_rails['omniauth_enabled'] = true
gitlab_rails['omniauth_allow_single_sign_on'] = false
gitlab_rails['block_auto_created_users'] = true
gitlab_rails['omniauth_providers'] = [
  {
    "name" => "google_oauth2",
    "app_id" => "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    "app_secret" => "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    "args" => { "access_type" => "offline", "approval_prompt" => "" }
  }
]
gitlab_rails['backup_keep_time'] = 604800