Heyhey, first thanks for the great frab. :D Here is my issue: I deleted a track and now the schedule cannot be exported anymore. The tracks table reads:

mysql> select * from tracks;
+----+---------------+---------------------------------+---------------------+---------------------+--------+
| id | conference_id | name | created_at | updated_at | color |
+----+---------------+---------------------------------+---------------------+---------------------+--------+
| 2 | 1 | name1 | 2018-10-11 22:18:34 | 2018-10-18 11:38:53 | dcfc7e |
| 3 | 1 | name2 | 2018-10-11 22:18:34 | 2018-10-12 15:24:20 | ffd257 |
| 4 | 1 | name3 | 2018-10-11 22:18:34 | 2018-10-12 15:23:45 | 7d85fa |
+----+---------------+---------------------------------+---------------------+---------------------+--------+

On rendering the log shows the fail:

D, [2018-10-25T12:36:27.659371 #22024] DEBUG -- : Track Load (0.2ms) SELECT tracks.* FROM tracks WHERE tracks.id = 1 ORDER BY tracks.name ASC LIMIT 1
I, [2018-10-25T12:36:27.670328 #22024] INFO -- : Rendered public/schedule/_events_by_track.html.haml (108.8ms)
I, [2018-10-25T12:36:27.670643 #22024] INFO -- : Rendered public/schedule/events.html.haml within layouts/public_schedule (115.5ms)
D, [2018-10-25T12:36:27.698446 #22024] DEBUG -- : (27.3ms) ROLLBACK
E, [2018-10-25T12:36:27.701994 #22024] ERROR -- : Sucker Punch job error for class: 'StaticProgramExportJob' args: [#<Conference id: 1, acronym: "xxx", title: "yyy", timezone: "Berlin", timeslot_duration: 5, default_timeslots: 4, max_timeslots: 100, feedback_enabled: true, created_at: "2018-06-17 23:16:19", updated_at: "2018-10-25 10:36:16", email: "[email protected]", program_export_base_url: "https://fahrplan.zzz.org", schedule_version: "alpha", schedule_public: true, color: "a1c854", ticket_type: "integrated", event_state_visible: true, schedule_custom_css: "#header {\r\n background-color: #a1c854;\r\n}", schedule_html_intro: "Test-Intro", default_recording_license: "CC BY", expenses_enabled: false, transport_needs_enabled: true, parent_id: nil, bulk_notification_enabled: true, logo_file_name: nil, logo_content_type: nil, logo_file_size: nil, logo_updated_at: nil, schedule_open: false, start_date: "2018-11-17 09:00:00", end_date: "2018-11-18 17:00:00">, "de"]
ActionView::Template::Error Couldn't find Track with 'id'=1

Thanks for reading
Laryllian