Pipeline Schedules Missing required keys id

Summary

We have one project in which the pipeline schedules tab throws an 500 error.

Steps to reproduce

Sadly this is the only project which does not work.

What is the current bug behavior?

If you click the Schedules tab you see the 500 error

What is the expected correct behavior?

I expect to see the schedules

Relevant logs and/or screenshots

ActionView::Template::Error (No route matches {:action=>"show", :controller=>"projects/commits", :id=>"", :namespace_id=>#<Group id: 144, name: "base", path: "base", owner_id: nil, created_at: "2017-06-01 09:08:41", updated_at: "2017-06-01 11:27:26", type: "Group", description: "", avatar: "example.png", share_with_group_lock: false, visibility_level: 0, request_access_enabled: false, deleted_at: nil, lfs_enabled: nil, description_html: "", parent_id: 143, require_two_factor_authentication: false, two_factor_grace_period: 48, cached_markdown_version: 1>, :project_id=>#<Project id: 286, name: "example", path: "example", description: "example", created_at: "2017-02-10 15:40:20", updated_at: "2017-06-01 09:26:12", creator_id: 7, namespace_id: 144, last_activity_at: "2017-07-04 11:04:52", import_url: nil, visibility_level: 0, archived: false, avatar: nil, import_status: "none", star_count: 1, import_type: nil, import_source: nil, import_error: nil, ci_id: nil, shared_runners_enabled: false, runners_token: "xxx", build_coverage_regex: nil, build_allow_git_fetch: true, build_timeout: 3600, pending_delete: false, public_builds: true, last_repository_check_failed: false, last_repository_check_at: "2017-06-11 18:20:16", container_registry_enabled: false, only_allow_merge_if_pipeline_succeeds: false, has_external_issue_tracker: false, repository_storage: "default", has_external_wiki: false, request_access_enabled: false, lfs_enabled: nil, description_html: "<p dir=\"auto\">example</p>", only_allow_merge_if_all_discussions_are_resolved: false, printing_merge_request_link_enabled: true, auto_cancel_pending_pipelines: 1, import_jid: nil, cached_markdown_version: 1, last_repository_updated_at: "2017-07-04 11:04:52">} missing required keys: [:id]):
     5:     %td.branch-name-cell
     6:       = icon('code-fork')
     7:       - if pipeline_schedule.ref
     8:         = link_to pipeline_schedule.ref, project_ref_path(@project, pipeline_schedule.ref), class: "ref-name"
     9:     %td
    10:       - if pipeline_schedule.last_pipeline
    11:         .status-icon-container{ class: "ci-status-icon-#{pipeline_schedule.last_pipeline.status}" }
  app/helpers/gitlab_routing_helper.rb:58:in `project_ref_path'
  app/views/projects/pipeline_schedules/_pipeline_schedule.html.haml:8:in `_app_views_projects_pipeline_schedules__pipeline_schedule_html_haml___3789170594598354480_113618160'
  app/views/projects/pipeline_schedules/_table.html.haml:12:in `_app_views_projects_pipeline_schedules__table_html_haml___3637774935116841827_58064140'
  app/views/projects/pipeline_schedules/index.html.haml:21:in `_app_views_projects_pipeline_schedules_index_html_haml__3795203117173264102_59001480'
  lib/gitlab/i18n.rb:39:in `with_locale'
  lib/gitlab/i18n.rb:45:in `with_user_locale'
  app/controllers/application_controller.rb:303:in `set_locale'
  lib/gitlab/performance_bar/peek_performance_bar_with_rack_body.rb:16:in `call'
  lib/gitlab/middleware/multipart.rb:93:in `call'
  lib/gitlab/request_profiler/middleware.rb:14:in `call'
  lib/gitlab/middleware/go.rb:16:in `call'
  lib/gitlab/etag_caching/middleware.rb:11:in `call'
  lib/gitlab/request_context.rb:18:in `call'