Error: filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62

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Nextcloud version: 21.0.0-9 *config.php shows 21.0.0.18
Operating system and version: Arch Linux 5.11.2.arch1-1
nginx version: 1.19.7-1
PHP version: 8.0.3-1

The issue you are facing:

I recently completed a fresh install of Nextcloud 21 on my headless Arch Linux server. I’ve been running Nextcloud for a couple years on my server. I am the only user.

After this install, I have many indentical errors in my Nextcloud log file:

Error: filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62

I’ll paste the full error log below.

Is this the first time you’ve seen this error? Yes

Steps to replicate it:

  1. Fresh install of Nextcloud 21 on Arch Linux, running nginx and PHP 8 (php-fpm)
  2. Log in to Nextcloud web UI
  3. Go to Settings, Logging, read the log file

The output of your Nextcloud log in Admin > Logging:

{"reqId":"b9aKKMPkPBA9X7Im7sUW","level":3,"time":"March 03, 2021 08:11:47","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"LorGwKiN8dWMoxH4Efnq","level":3,"time":"March 03, 2021 11:11:48","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"CwYNy4AJcUENymXMcQCp","level":3,"time":"March 03, 2021 14:11:49","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"eM4iaClpPKsmuriJFXWe","level":3,"time":"March 03, 2021 17:11:51","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"rgElnjCVLQqkVW3PBwlr","level":3,"time":"March 03, 2021 20:26:52","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"ahBprMvRpP1yQr86IkSM","level":3,"time":"March 03, 2021 23:26:55","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"fhA2flkv5ujkDlwia3o8","level":3,"time":"March 04, 2021 02:41:54","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"vMaJXRpcZfTqkymCEGEo","level":3,"time":"March 04, 2021 05:41:55","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":{"Exception":"Error","Message":"filesize(): stat failed for /var/lib/nextcloud/data/flow.log at /usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php#62","Code":0,"Trace":[{"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/public/Log/RotationTrait.php","line":62,"function":"filesize"},{"file":"/usr/share/webapps/nextcloud/apps/workflowengine/lib/BackgroundJobs/Rotate.php","line":49,"function":"shouldRotateBySize","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/Job.php","line":52,"function":"run","class":"OCA\\WorkflowEngine\\BackgroundJobs\\Rotate","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/BackgroundJob/TimedJob.php","line":59,"function":"execute","class":"OC\\BackgroundJob\\Job","type":"->"},{"file":"/usr/share/webapps/nextcloud/cron.php","line":128,"function":"execute","class":"OC\\BackgroundJob\\TimedJob","type":"->"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"--","version":"21.0.0.18"}
{"reqId":"texojtt9NgCz7Y3GztkZ","level":3,"time":"March 04, 2021 06:44:35","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/core/preview?fileId=2872&x=32&y=32","message":"Required parameter $internalPath follows optional parameter $mountId at /usr/share/webapps/nextcloud/lib/private/Files/Config/CachedMountFileInfo.php#34","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}
{"reqId":"KOuR6UvWsFBtLptD6xXV","level":3,"time":"March 04, 2021 06:44:42","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/index.php/apps/files/ajax/getstoragestats.php?dir=%2F","message":"Required parameter $tagManager follows optional parameter $fileIdentifier at /usr/share/webapps/nextcloud/apps/files/lib/Helper.php#220","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}
{"reqId":"GXMVDh9m5ky6AO3nZCD0","level":3,"time":"March 04, 2021 06:44:52","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/apps/richdocuments/index?fileId=2872&requesttoken=czPJKWMMXx3O8hDPfdDIykDZ2xBY0dRu7Elc55QOcqg%3D%3AH1bmeBN2GF%2BpolH%2FJLu8qyyzjF8XvpsC2WYzvaZEOO8%3D","message":{"Exception":"Error","Message":"Function libxml_disable_entity_loader() is deprecated at /var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php#42","Code":0,"Trace":[{"file":"/var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php","line":42,"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/TokenManager.php","line":217,"function":"getUrlSrc","class":"OCA\\Richdocuments\\WOPI\\Parser","type":"->"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/Controller/DocumentController.php","line":256,"function":"getToken","class":"OCA\\Richdocuments\\TokenManager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":218,"function":"index","class":"OCA\\Richdocuments\\Controller\\DocumentController","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":127,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/App.php","line":157,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/Route/Router.php","line":302,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/base.php","line":993,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/usr/share/webapps/nextcloud/index.php","line":37,"function":"handleRequest","class":"OC","type":"::"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}
{"reqId":"GXMVDh9m5ky6AO3nZCD0","level":3,"time":"March 04, 2021 06:44:52","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/apps/richdocuments/index?fileId=2872&requesttoken=czPJKWMMXx3O8hDPfdDIykDZ2xBY0dRu7Elc55QOcqg%3D%3AH1bmeBN2GF%2BpolH%2FJLu8qyyzjF8XvpsC2WYzvaZEOO8%3D","message":{"Exception":"Error","Message":"Function libxml_disable_entity_loader() is deprecated at /var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php#44","Code":0,"Trace":[{"file":"/var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php","line":44,"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/TokenManager.php","line":217,"function":"getUrlSrc","class":"OCA\\Richdocuments\\WOPI\\Parser","type":"->"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/Controller/DocumentController.php","line":256,"function":"getToken","class":"OCA\\Richdocuments\\TokenManager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":218,"function":"index","class":"OCA\\Richdocuments\\Controller\\DocumentController","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":127,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/App.php","line":157,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/Route/Router.php","line":302,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/base.php","line":993,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/usr/share/webapps/nextcloud/index.php","line":37,"function":"handleRequest","class":"OC","type":"::"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}
{"reqId":"nAl5uOsWah2QrNSsxy3w","level":3,"time":"March 04, 2021 06:45:00","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/apps/richdocuments/index?fileId=13806&requesttoken=czPJKWMMXx3O8hDPfdDIykDZ2xBY0dRu7Elc55QOcqg%3D%3AH1bmeBN2GF%2BpolH%2FJLu8qyyzjF8XvpsC2WYzvaZEOO8%3D","message":{"Exception":"Error","Message":"Function libxml_disable_entity_loader() is deprecated at /var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php#42","Code":0,"Trace":[{"file":"/var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php","line":42,"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/TokenManager.php","line":217,"function":"getUrlSrc","class":"OCA\\Richdocuments\\WOPI\\Parser","type":"->"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/Controller/DocumentController.php","line":256,"function":"getToken","class":"OCA\\Richdocuments\\TokenManager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":218,"function":"index","class":"OCA\\Richdocuments\\Controller\\DocumentController","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":127,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/App.php","line":157,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/Route/Router.php","line":302,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/base.php","line":993,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/usr/share/webapps/nextcloud/index.php","line":37,"function":"handleRequest","class":"OC","type":"::"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}
{"reqId":"nAl5uOsWah2QrNSsxy3w","level":3,"time":"March 04, 2021 06:45:00","remoteAddr":"123.123.123.123","user":"myUser","app":"PHP","method":"GET","url":"/apps/richdocuments/index?fileId=13806&requesttoken=czPJKWMMXx3O8hDPfdDIykDZ2xBY0dRu7Elc55QOcqg%3D%3AH1bmeBN2GF%2BpolH%2FJLu8qyyzjF8XvpsC2WYzvaZEOO8%3D","message":{"Exception":"Error","Message":"Function libxml_disable_entity_loader() is deprecated at /var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php#44","Code":0,"Trace":[{"file":"/var/lib/nextcloud/apps/richdocuments/lib/WOPI/Parser.php","line":44,"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/TokenManager.php","line":217,"function":"getUrlSrc","class":"OCA\\Richdocuments\\WOPI\\Parser","type":"->"},{"file":"/var/lib/nextcloud/apps/richdocuments/lib/Controller/DocumentController.php","line":256,"function":"getToken","class":"OCA\\Richdocuments\\TokenManager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":218,"function":"index","class":"OCA\\Richdocuments\\Controller\\DocumentController","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":127,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/AppFramework/App.php","line":157,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/usr/share/webapps/nextcloud/lib/private/Route/Router.php","line":302,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/usr/share/webapps/nextcloud/lib/base.php","line":993,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/usr/share/webapps/nextcloud/index.php","line":37,"function":"handleRequest","class":"OC","type":"::"}],"File":"/usr/share/webapps/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 OPR/74.0.3911.160","version":"21.0.0.18"}

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

{
    "datadirectory": "***REMOVED SENSITIVE VALUE***",
    "log_type": "file",
    "logfile": "\/var\/log\/nextcloud.log",
    "logfilemode": 416,
    "loglevel": 3,
    "logdateformat": "F d, Y H:i:s",
    "logtimezone": "America\/Chicago",
    "apps_paths": [
        {
            "path": "\/usr\/share\/webapps\/nextcloud\/apps",
            "url": "\/apps",
            "writable": false
        },
        {
            "path": "\/var\/lib\/nextcloud\/apps",
            "url": "\/wapps",
            "writable": true
        }
    ],
    "instanceid": "***REMOVED SENSITIVE VALUE***",
    "passwordsalt": "***REMOVED SENSITIVE VALUE***",
    "secret": "***REMOVED SENSITIVE VALUE***",
    "trusted_domains": [
        "my.domain.com"
    ],
    "dbtype": "mysql",
    "version": "21.0.0.18",
    "overwrite.cli.url": "https:\/\/my.domain.com",
    "check_for_working_htaccess": false,
    "dbname": "***REMOVED SENSITIVE VALUE***",
    "dbhost": "***REMOVED SENSITIVE VALUE***",
    "dbport": "",
    "dbtableprefix": "oc_",
    "mysql.utf8mb4": true,
    "dbuser": "***REMOVED SENSITIVE VALUE***",
    "dbpassword": "***REMOVED SENSITIVE VALUE***",
    "installed": true,
    "force_language": "en",
    "default_phone_region": "US",
    "force_locale": "en_US",
    "mail_smtpmode": "smtp",
    "mail_smtpsecure": "ssl",
    "mail_sendmailmode": "smtp",
    "mail_from_address": "***REMOVED SENSITIVE VALUE***",
    "mail_domain": "***REMOVED SENSITIVE VALUE***",
    "mail_smtpauthtype": "LOGIN",
    "mail_smtpauth": 1,
    "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
    "mail_smtpport": "465",
    "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
    "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
    "memcache.local": "\\OC\\Memcache\\APCu",
    "memcache.locking": "\\OC\\Memcache\\Redis",
    "redis": {
        "host": "***REMOVED SENSITIVE VALUE***",
        "port": 0,
        "dbindex": 0,
        "password": "***REMOVED SENSITIVE VALUE***",
        "timeout": 1.5
    },
    "app_install_overwrite": [
        "richdocuments"
    ],
    "maintenance": false
}

The output of your nginx log in /var/log/____:

2021/03/04 06:44:52 [warn] 965#965: *63 an upstream response is buffered to a temporary file /var/lib/nginx/proxy/1/00/0000000001 while reading upstream, client: 123.123.123.123, server: my.domain.com, request: "GET /loleaflet/1bc2423/bundle.js HTTP/2.0", upstream: "https://127.0.0.1:9980/loleaflet/1bc2423/bundle.js", host: "my.domain.com"
2021/03/04 06:44:52 [warn] 965#965: *63 an upstream response is buffered to a temporary file /var/lib/nginx/proxy/2/00/0000000002 while reading upstream, client: 123.123.123.123, server: my.domain.com, request: "GET /loleaflet/1bc2423/bundle.css HTTP/2.0", upstream: "https://127.0.0.1:9980/loleaflet/1bc2423/bundle.css", host: "my.domain.com"

Found this for you. Sorry without solution:
NC 21 Error: filesize(): stat failed for /data/flow.log at /lib/public/Log/RotationTrait.php#62 · Issue #25813 · nextcloud/server · GitHub

Thanks. I added a comment at github as well.

I do not considered this solved yet. Hopefully, it will receive some attention soon.