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In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 20.0.5): Nextcloud Hub 7 (28.0.3)
Operating system and version (eg, Ubuntu 20.04): Ubuntu 23.10
Docker version: 25.0.3
Docker images: ‘nginx and mariadb:10.6’
PHP version (eg, 7.4): 8.2.16
The issue you are facing:
Is this the first time you’ve seen this error? (Y):
Steps to replicate it:
- Create VM of Ubuntu 23.10 minimal on proxmox
- Install docker and docker compose plugin
- run docker compose up -d with the nextcloud:fpm image, nginx, mariadb and a cron image as well.
The output of your Nextcloud log in Admin > Logging:
{
"reqId": "ajGEpT5SJ4pSyb1cd5Gl",
"level": 3,
"time": "2024-03-07T16:43:03+00:00",
"remoteAddr": "10.30.2.201",
"user": "compukid",
"app": "index",
"method": "GET",
"url": "/core/preview?fileId=49&x=256&y=256&c=76b16b7a7459fc9bab9390be2b403d9e",
"message": "Could not get appdata folder for preview",
"userAgent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36",
"version": "28.0.3.2",
"exception": {
"Exception": "RuntimeException",
"Message": "Could not get appdata folder for preview",
"Code": 0,
"Trace": [
{
"file": "/var/www/html/lib/private/Files/AppData/AppData.php",
"line": 147,
"function": "getAppDataFolder",
"class": "OC\\Files\\AppData\\AppData",
"type": "->",
"args": []
},
{
"file": "/var/www/html/lib/private/Preview/Storage/Root.php",
"line": 74,
"function": "newFolder",
"class": "OC\\Files\\AppData\\AppData",
"type": "->",
"args": [
"f/4/5/7/c/5/4/49"
]
},
{
"file": "/var/www/html/lib/private/Preview/Generator.php",
"line": 607,
"function": "newFolder",
"class": "OC\\Preview\\Storage\\Root",
"type": "->",
"args": [
"49"
]
},
{
"file": "/var/www/html/lib/private/Preview/Generator.php",
"line": 133,
"function": "getPreviewFolder",
"class": "OC\\Preview\\Generator",
"type": "->",
"args": [
[
"OC\\Files\\Node\\File"
]
]
},
{
"file": "/var/www/html/lib/private/Preview/Generator.php",
"line": 110,
"function": "generatePreviews",
"class": "OC\\Preview\\Generator",
"type": "->",
"args": [
[
"OC\\Files\\Node\\File"
],
[
[
256,
256,
true,
"fill"
]
],
"image/png"
]
},
{
"file": "/var/www/html/lib/private/PreviewManager.php",
"line": 187,
"function": "getPreview",
"class": "OC\\Preview\\Generator",
"type": "->",
"args": [
[
"OC\\Files\\Node\\File"
],
256,
256,
true,
"fill",
null
]
},
{
"file": "/var/www/html/core/Controller/PreviewController.php",
"line": 173,
"function": "getPreview",
"class": "OC\\PreviewManager",
"type": "->",
"args": [
[
"OC\\Files\\Node\\File"
],
256,
256,
true,
"fill"
]
},
{
"file": "/var/www/html/core/Controller/PreviewController.php",
"line": 141,
"function": "fetchPreview",
"class": "OC\\Core\\Controller\\PreviewController",
"type": "->",
"args": [
[
"OC\\Files\\Node\\File"
],
256,
256,
false,
true,
"fill",
false
]
},
{
"file": "/var/www/html/lib/private/AppFramework/Http/Dispatcher.php",
"line": 230,
"function": "getPreviewByFileId",
"class": "OC\\Core\\Controller\\PreviewController",
"type": "->",
"args": [
49,
256,
256,
false,
true,
"fill",
false
]
},
{
"file": "/var/www/html/lib/private/AppFramework/Http/Dispatcher.php",
"line": 137,
"function": "executeController",
"class": "OC\\AppFramework\\Http\\Dispatcher",
"type": "->",
"args": [
[
"OC\\Core\\Controller\\PreviewController"
],
"getPreviewByFileId"
]
},
{
"file": "/var/www/html/lib/private/AppFramework/App.php",
"line": 184,
"function": "dispatch",
"class": "OC\\AppFramework\\Http\\Dispatcher",
"type": "->",
"args": [
[
"OC\\Core\\Controller\\PreviewController"
],
"getPreviewByFileId"
]
},
{
"file": "/var/www/html/lib/private/Route/Router.php",
"line": 315,
"function": "main",
"class": "OC\\AppFramework\\App",
"type": "::",
"args": [
"OC\\Core\\Controller\\PreviewController",
"getPreviewByFileId",
[
"OC\\AppFramework\\DependencyInjection\\DIContainer"
],
[
"core.Preview.getPreviewByFileId"
]
]
},
{
"file": "/var/www/html/lib/base.php",
"line": 1069,
"function": "match",
"class": "OC\\Route\\Router",
"type": "->",
"args": [
"/core/preview"
]
},
{
"file": "/var/www/html/index.php",
"line": 39,
"function": "handleRequest",
"class": "OC",
"type": "::",
"args": []
}
],
"File": "/var/www/html/lib/private/Files/AppData/AppData.php",
"Line": 108,
"message": "Could not get appdata folder for preview",
"exception": [],
"CustomMessage": "Could not get appdata folder for preview"
},
"id": "65eb1a3b34014"
}
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'memcache.local' => '\\OC\\Memcache\\APCu',
'apps_paths' =>
array (
0 =>
array (
'path' => '/var/www/html/apps',
'url' => '/apps',
'writable' => false,
),
1 =>
array (
'path' => '/var/www/html/custom_apps',
'url' => '/custom_apps',
'writable' => true,
),
),
'upgrade.disable-web' => true,
'instanceid' => 'oc8p86z3au4v',
'passwordsalt' => 'N/A',
'secret' => 'N/A',
'trusted_domains' =>
array (
0 => 'my.domain.com',
1 => '10.30.2.202:8180',
),
'datadirectory' => '/var/www/html/data',
'dbtype' => 'mysql',
'version' => '28.0.3.2',
'overwrite.cli.url' => 'https://my.domain.com',
'dbname' => 'nextcloud',
'dbhost' => 'db',
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => 'nextcloud',
'dbpassword' => 'N/A',
'installed' => true,
'overwriteprotocol' => 'https',
'maintenance_window_start' => 2,
'default_phone_region' => 'US',
'enable_previews' => true,
);
The output of your Apache/nginx/system log in /var/log/____:
Having trouble getting nginx log. When I run the cat or tail command in docker it hangs until I hit CTRL+C to escape with no output.
Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.
{"reqId":"pSe05Xef1KD2ygshEOeF","level":3,"time":"2024-03-07T16:42:36+00:00","remoteAddr":"10.30.2.201","user":"compukid","app":"index","method":"GET","url":"/apps/theming/icon?v=0","message":"Could not create folder \"/appdata_oc8p86z3au4v/theming/global\"","userAgent":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36","version":"28.0.3.2","exception":{"Exception":"OCP\\Files\\NotPermittedException","Message":"Could not create folder \"/appdata_oc8p86z3au4v/theming/global\"","Code":0,"Trace":[{"file":"/var/www/html/lib/private/Files/AppData/AppData.php","line":147,"function":"newFolder","class":"OC\\Files\\Node\\Folder","type":"->","args":["global"]},{"file":"/var/www/html/apps/theming/lib/ImageManager.php","line":367,"function":"newFolder","class":"OC\\Files\\AppData\\AppData","type":"->","args":["global"]},{"file":"/var/www/html/apps/theming/lib/ImageManager.php","line":101,"function":"getRootFolder","class":"OCA\\Theming\\ImageManager","type":"->","args":[]},{"file":"/var/www/html/apps/theming/lib/Controller/IconController.php","line":176,"function":"getImage","class":"OCA\\Theming\\ImageManager","type":"->","args":["favicon"]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":230,"function":"getTouchIcon","class":"OCA\\Theming\\Controller\\IconController","type":"->","args":["core"]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":137,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OCA\\Theming\\Controller\\IconController"],"getTouchIcon"]},{"file":"/var/www/html/lib/private/AppFramework/App.php","line":184,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OCA\\Theming\\Controller\\IconController"],"getTouchIcon"]},{"file":"/var/www/html/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OCA\\Theming\\Controller\\IconController","getTouchIcon",["OC\\AppFramework\\DependencyInjection\\DIContainer"],["core","theming.Icon.getTouchIcon"]]},{"file":"/var/www/html/lib/base.php","line":1069,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/apps/theming/icon"]},{"file":"/var/www/html/index.php","line":39,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/var/www/html/lib/private/Files/Node/Folder.php","Line":162,"message":"Could not create folder \"/appdata_oc8p86z3au4v/theming/global\"","exception":{},"CustomMessage":"Could not create folder \"/appdata_oc8p86z3au4v/theming/global\""}}
{"reqId":"ajGEpT5SJ4pSyb1cd5Gl","level":3,"time":"2024-03-07T16:43:03+00:00","remoteAddr":"10.30.2.201","user":"compukid","app":"index","method":"GET","url":"/core/preview?fileId=49&x=256&y=256&c=76b16b7a7459fc9bab9390be2b403d9e","message":"Could not get appdata folder for preview","userAgent":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36","version":"28.0.3.2","exception":{"Exception":"RuntimeException","Message":"Could not get appdata folder for preview","Code":0,"Trace":[{"file":"/var/www/html/lib/private/Files/AppData/AppData.php","line":147,"function":"getAppDataFolder","class":"OC\\Files\\AppData\\AppData","type":"->","args":[]},{"file":"/var/www/html/lib/private/Preview/Storage/Root.php","line":74,"function":"newFolder","class":"OC\\Files\\AppData\\AppData","type":"->","args":["f/4/5/7/c/5/4/49"]},{"file":"/var/www/html/lib/private/Preview/Generator.php","line":607,"function":"newFolder","class":"OC\\Preview\\Storage\\Root","type":"->","args":["49"]},{"file":"/var/www/html/lib/private/Preview/Generator.php","line":133,"function":"getPreviewFolder","class":"OC\\Preview\\Generator","type":"->","args":[["OC\\Files\\Node\\File"]]},{"file":"/var/www/html/lib/private/Preview/Generator.php","line":110,"function":"generatePreviews","class":"OC\\Preview\\Generator","type":"->","args":[["OC\\Files\\Node\\File"],[[256,256,true,"fill"]],"image/png"]},{"file":"/var/www/html/lib/private/PreviewManager.php","line":187,"function":"getPreview","class":"OC\\Preview\\Generator","type":"->","args":[["OC\\Files\\Node\\File"],256,256,true,"fill",null]},{"file":"/var/www/html/core/Controller/PreviewController.php","line":173,"function":"getPreview","class":"OC\\PreviewManager","type":"->","args":[["OC\\Files\\Node\\File"],256,256,true,"fill"]},{"file":"/var/www/html/core/Controller/PreviewController.php","line":141,"function":"fetchPreview","class":"OC\\Core\\Controller\\PreviewController","type":"->","args":[["OC\\Files\\Node\\File"],256,256,false,true,"fill",false]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":230,"function":"getPreviewByFileId","class":"OC\\Core\\Controller\\PreviewController","type":"->","args":[49,256,256,false,true,"fill",false]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":137,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OC\\Core\\Controller\\PreviewController"],"getPreviewByFileId"]},{"file":"/var/www/html/lib/private/AppFramework/App.php","line":184,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OC\\Core\\Controller\\PreviewController"],"getPreviewByFileId"]},{"file":"/var/www/html/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OC\\Core\\Controller\\PreviewController","getPreviewByFileId",["OC\\AppFramework\\DependencyInjection\\DIContainer"],["core.Preview.getPreviewByFileId"]]},{"file":"/var/www/html/lib/base.php","line":1069,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/core/preview"]},{"file":"/var/www/html/index.php","line":39,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/var/www/html/lib/private/Files/AppData/AppData.php","Line":108,"message":"Could not get appdata folder for preview","exception":{},"CustomMessage":"Could not get appdata folder for preview"}}
I would like to clean up the errors on the nextcloud log and not sure how. I did see similar issues to mine. One solution was a permission issue and I confirmed the app image has all files owned by www-data and still didn’t fix the issue. Not sure what else it could be.
