Here is the log export:
{"reqId":"AOshhbY460nvRuydDfn5","level":1,"time":"2026-06-18T07:29:47+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"GET","url":"/remote.php/dav/files/Natascha/Cloud%20Daten/Dienstplanung/Dienstplan%202026/Dienstplan%202026.ods","scriptName":"/remote.php","message":"The app config key dav/enableCalendarFederation is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"0f004902-dd9c-43c5-84f3-e46815f77853","data":[ ]}
{"reqId":"AOshhbY460nvRuydDfn5","level":1,"time":"2026-06-18T07:29:47+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"GET","url":"/remote.php/dav/files/Natascha/Cloud%20Daten/Dienstplanung/Dienstplan%202026/Dienstplan%202026.ods","scriptName":"/remote.php","message":"The app config key dav/sendInvitations is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"0f004902-dd9c-43c5-84f3-e46815f77853","data":[ ]}
{"reqId":"AMRtMs782BSs9qQynKIY","level":1,"time":"2026-06-18T07:29:48+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Natascha/","scriptName":"/remote.php","message":"The app config key dav/enableCalendarFederation is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"ea5c4fbc-f544-44ca-b4d1-693f03e63193","data":[ ]}
{"reqId":"AMRtMs782BSs9qQynKIY","level":1,"time":"2026-06-18T07:29:48+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Natascha/","scriptName":"/remote.php","message":"The app config key dav/sendInvitations is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"ea5c4fbc-f544-44ca-b4d1-693f03e63193","data":[ ]}
{"reqId":"R0K1gy2nn3zLofH3xSn7","level":1,"time":"2026-06-18T07:29:48+00:00","remoteAddr":"80.147.74.92","user":"Harald","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Harald/Cloud%20Daten/Revierdienst/1%20Revier%20Mo%20-%20Do","scriptName":"/remote.php","message":"The app config key dav/enableCalendarFederation is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"76327309-7b5d-4f84-8ed8-29d8ea7ab858","data":[ ]}
{"reqId":"R0K1gy2nn3zLofH3xSn7","level":1,"time":"2026-06-18T07:29:48+00:00","remoteAddr":"80.147.74.92","user":"Harald","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Harald/Cloud%20Daten/Revierdienst/1%20Revier%20Mo%20-%20Do","scriptName":"/remote.php","message":"The app config key dav/sendInvitations is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"76327309-7b5d-4f84-8ed8-29d8ea7ab858","data":[ ]}
{"reqId":"HQhxPqRj0Obky7XdPliJ","level":1,"time":"2026-06-18T07:29:53+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Natascha/","scriptName":"/remote.php","message":"The app config key dav/enableCalendarFederation is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"035492a6-dbbb-4bdb-9ccd-e0ca57c6e739","data":[ ]}
{"reqId":"HQhxPqRj0Obky7XdPliJ","level":1,"time":"2026-06-18T07:29:53+00:00","remoteAddr":"80.147.74.92","user":"Natascha","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Natascha/","scriptName":"/remote.php","message":"The app config key dav/sendInvitations is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26200 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"035492a6-dbbb-4bdb-9ccd-e0ca57c6e739","data":[ ]}
{"reqId":"PUhFsyYWvtMEGLZdksS4","level":1,"time":"2026-06-18T07:30:10+00:00","remoteAddr":"80.147.74.92","user":"Leitstelle","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Leitstelle/Cloud%20Daten/Dienstplanung/Dienstplan%202026","scriptName":"/remote.php","message":"The app config key dav/enableCalendarFederation is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26100 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"7852e48a-c3d0-4127-ba2c-ad6fcd01b22f","data":[ ]}
{"reqId":"PUhFsyYWvtMEGLZdksS4","level":1,"time":"2026-06-18T07:30:10+00:00","remoteAddr":"80.147.74.92","user":"Leitstelle","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/Leitstelle/Cloud%20Daten/Dienstplanung/Dienstplan%202026","scriptName":"/remote.php","message":"The app config key dav/sendInvitations is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows) mirall/33.0.5 (build 20260519) (Nextcloud, windows-10.0.26100 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"33.0.5.1","clientReqId":"7852e48a-c3d0-4127-ba2c-ad6fcd01b22f","data":[ ]}
{"reqId":"cZ97e3EwejSS945hlPJ1","level":1,"time":"2026-06-18T07:30:10+00:00","remoteAddr":"52.87.72.16","user":"--","app":"no app in context","method":"HEAD","url":"/index.php/login","scriptName":"/index.php","message":"The app config key dav/hide_absence_settings is not defined in the config lexicon","userAgent":"Mozilla/5.0+(compatible; UptimeRobot/2.0; http://www.uptimerobot.com/)","version":"33.0.5.1","data":[ ]}
{"reqId":"BCtoJZbWLp19przbCrWb","level":1,"time":"2026-06-18T07:30:33+00:00","remoteAddr":"80.147.74.92","user":"Admin","app":"no app in context","method":"GET","url":"/index.php/settings/admin/logging","scriptName":"/index.php","message":"The app config key dav/hide_absence_settings is not defined in the config lexicon","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36 Edg/149.0.0.0","version":"33.0.5.1","data":[ ]}
{"reqId":"a3kZgEjQNX29Gu97ezCh","level":1,"time":"2026-06-18T07:30:57+00:00","remoteAddr":"","user":"--","app":"related_resources","method":"","url":"--","scriptName":"/snap/nextcloud/53545/htdocs/occ","message":"Could not resolve OCA\\Circles\\CirclesManager! Class "OCA\\Circles\\CirclesManager" does not exist","userAgent":"--","version":"33.0.5.1","occ_command":\["/snap/nextcloud/53545/htdocs/occ","config:system:set"\],"data":{"app":"related_resources"}}
{"reqId":"bThsfstbJAUysD4H5ZTM","level":2,"time":"2026-06-18T07:46:35+00:00","remoteAddr":"","user":"--","app":"mail","method":"","url":"--","scriptName":"/snap/nextcloud/53545/htdocs/cron.php","message":"Could not get attachment names","userAgent":"--","version":"33.0.5.1","occ_command":\["/snap/nextcloud/53545/htdocs/cron.php"\],"exception":{"Exception":"OCA\\Mail\\Exception\\ServiceException","Message":"Could not load message","Code":0,"Trace":\[{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/Attachment/AttachmentService.php","line":303,"function":"getImapMessage","class":"OCA\\Mail\\Service\\MailManager","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/PreviewEnhancer.php","line":75,"function":"getAttachmentNames","class":"OCA\\Mail\\Service\\Attachment\\AttachmentService","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/PreprocessingService.php","line":59,"function":"process","class":"OCA\\Mail\\IMAP\\PreviewEnhancer","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/BackgroundJob/PreviewEnhancementProcessingJob.php","line":77,"function":"process","class":"OCA\\Mail\\Service\\PreprocessingService","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/Job.php","line":50,"function":"run","class":"OCA\\Mail\\BackgroundJob\\PreviewEnhancementProcessingJob","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/TimedJob.php","line":85,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/core/Service/CronService.php","line":176,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/core/Service/CronService.php","line":98,"function":"runCli","class":"OC\\Core\\Service\\CronService","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/cron.php","line":52,"function":"run","class":"OC\\Core\\Service\\CronService","type":"->"}\],"File":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/MailManager.php","Line":180,"Previous":{"Exception":"OCP\\AppFramework\\Db\\DoesNotExistException","Message":"Message does not exist","Code":0,"Trace":\[{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/MailManager.php","line":172,"function":"find","class":"OCA\\Mail\\IMAP\\MessageMapper","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/Attachment/AttachmentService.php","line":303,"function":"getImapMessage","class":"OCA\\Mail\\Service\\MailManager","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/PreviewEnhancer.php","line":75,"function":"getAttachmentNames","class":"OCA\\Mail\\Service\\Attachment\\AttachmentService","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/PreprocessingService.php","line":59,"function":"process","class":"OCA\\Mail\\IMAP\\PreviewEnhancer","type":"->"},{"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/BackgroundJob/PreviewEnhancementProcessingJob.php","line":77,"function":"process","class":"OCA\\Mail\\Service\\PreprocessingService","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/Job.php","line":50,"function":"run","class":"OCA\\Mail\\BackgroundJob\\PreviewEnhancementProcessingJob","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/TimedJob.php","line":85,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/core/Service/CronService.php","line":176,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/core/Service/CronService.php","line":98,"function":"runCli","class":"OC\\Core\\Service\\CronService","type":"->"},{"file":"/snap/nextcloud/53545/htdocs/cron.php","line":52,"function":"run","class":"OC\\Core\\Service\\CronService","type":"->"}\],"File":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/MessageMapper.php","Line":85},"message":"Could not get attachment names","exception":"{"class":"OCA\\Mail\\Exception\\ServiceException","message":"Could not load message","code":0,"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/MailManager.php:180","trace":"#0 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/Attachment/AttachmentService.php(303): OCA\\Mail\\Service\\MailManager->getImapMessage()\\n#1 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/PreviewEnhancer.php(75): OCA\\Mail\\Service\\Attachment\\AttachmentService->getAttachmentNames()\\n#2 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/PreprocessingService.php(59): OCA\\Mail\\IMAP\\PreviewEnhancer->process()\\n#3 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/BackgroundJob/PreviewEnhancementProcessingJob.php(77): OCA\\Mail\\Service\\PreprocessingService->process()\\n#4 /snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/Job.php(50): OCA\\Mail\\BackgroundJob\\PreviewEnhancementProcessingJob->run()\\n#5 /snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/TimedJob.php(85): OCP\\BackgroundJob\\Job->start()\\n#6 /snap/nextcloud/53545/htdocs/core/Service/CronService.php(176): OCP\\BackgroundJob\\TimedJob->start()\\n#7 /snap/nextcloud/53545/htdocs/core/Service/CronService.php(98): OC\\Core\\Service\\CronService->runCli()\\n#8 /snap/nextcloud/53545/htdocs/cron.php(52): OC\\Core\\Service\\CronService->run()\\n#9 {main}","previous":{"class":"OCP\\AppFramework\\Db\\DoesNotExistException","message":"Message does not exist","code":0,"file":"/var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/MessageMapper.php:85","trace":"#0 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/MailManager.php(172): OCA\\Mail\\IMAP\\MessageMapper->find()\\n#1 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/Attachment/AttachmentService.php(303): OCA\\Mail\\Service\\MailManager->getImapMessage()\\n#2 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/IMAP/PreviewEnhancer.php(75): OCA\\Mail\\Service\\Attachment\\AttachmentService->getAttachmentNames()\\n#3 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/Service/PreprocessingService.php(59): OCA\\Mail\\IMAP\\PreviewEnhancer->process()\\n#4 /var/snap/nextcloud/53545/nextcloud/extra-apps/mail/lib/BackgroundJob/PreviewEnhancementProcessingJob.php(77): OCA\\Mail\\Service\\PreprocessingService->process()\\n#5 /snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/Job.php(50): OCA\\Mail\\BackgroundJob\\PreviewEnhancementProcessingJob->run()\\n#6 /snap/nextcloud/53545/htdocs/lib/public/BackgroundJob/TimedJob.php(85): OCP\\BackgroundJob\\Job->start()\\n#7 /snap/nextcloud/53545/htdocs/core/Service/CronService.php(176): OCP\\BackgroundJob\\TimedJob->start()\\n#8 /snap/nextcloud/53545/htdocs/core/Service/CronService.php(98): OC\\Core\\Service\\CronService->runCli()\\n#9 /snap/nextcloud/53545/htdocs/cron.php(52): OC\\Core\\Service\\CronService->run()\\n#10 {main}"}}","messageId":"12717","CustomMessage":"Could not get attachment names"}}