You don't have permission to upload or create files here on Blackberry 10

Nextcloud version (eg, 10.0.2):11.0.1
Operating system and version (eg, Ubuntu 16.04):Arch Linux ARM
Apache or nginx version (eg, Apache 2.4.25): 2.4.25
PHP version (eg, 5.6):7.1.2
Is this the first time you’ve seen this error and can you replicate it?:yes, it replicable on permanent basis

The issue you are facing:
When logging into Nextcloud in Web browser, message “You don’t have permission to upload or create files here” appears in “File” app in the root and all subfolders, so I can’t preview pictures, for example. At other hand, if I switch to “Gallery” app everything looks fine, and privew is possible.
Such manner presents on Blackberry 10 device only; I tried Windows desktop, Windows Phone and Android and everything is OK

The output of your Nextcloud log in Admin > Logging:

Undefined offset: 0 at /usr/share/webapps/nextcloud/apps/gallery/environment/environment.php#360
ExceptionCould not locate node linked to ID: 0
ExceptionCould not locate node linked to ID: 0

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

<?php
$CONFIG = array (
'instanceid' => 'oc9jhbo98l7k',
'passwordsalt' => 'oxWnzhvHa6LVXsirhFMJ0lD803CdIW',
'secret' => 'J8fpE5kE+FPmuBZss0W84R6W3dBiO22akRAm9bWK/Xgu1yYn',
'trusted_domains' => 
array (
0 => 'LocalIP',
1 => 'WebIP',
),
'memcache.local' => '\\OC\\Memcache\\APCu',
'datadirectory' => '/media/usbhdd',
'overwrite.cli.url' => 'LocalIP/nextcloud',
'dbtype' => 'mysql',
'version' => '11.0.1.2',
'dbname' => 'nextcloud',
'dbhost' => 'localhost',
'dbport' => '',
'dbtableprefix' => 'oc_',
'dbuser' => 'oc_RaspberryClou',
'dbpassword' => 'mJumGfFEqYyA8N9tuYjbJC60M6pXPq',
'logtimezone' => 'UTC',
'installed' => true,
'maintenance' => false,
'theme' => '',
'loglevel' => 2,
'filelocking.enabled' => true,
'mail_smtpmode' => 'sendmail',
'mail_from_address' => 'user',
'mail_domain' => 'mail.com',
);

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

"GET /index.php/login HTTP/1.1" 200 17441
"GET /index.php/core/js/oc.js?v=77b85878be7fb4cb029acdd4cffdbeeb HTTP/1.1" 200 4271
"GET /index.php/apps/theming/styles?v=0 HTTP/1.1" 200 38
"GET /index.php/apps/theming/js/theming?v=0 HTTP/1.1" 200 321
"POST /index.php/login HTTP/1.1" 303 -
"GET /index.php/apps/files/ HTTP/1.1" 200 56967
"GET /index.php/core/js/oc.js?v=77b85878be7fb4cb029acdd4cffdbeeb HTTP/1.1" 200 4324
"GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 509
"PROPFIND /remote.php/webdav/ HTTP/1.1" 207 2519
"GET /index.php/apps/gallery/config?extramediatypes=1 HTTP/1.1" 200 102
"GET /index.php/apps/systemtags/lastused HTTP/1.1" 200 2
"GET /index.php/avatar/User/72?v=0 HTTP/1.1" 200 36
"PROPFIND /remote.php/webdav/ HTTP/1.1" 207 2519
"GET /index.php/apps/files/ajax/getstoragestats.php?dir=%2F HTTP/1.1" 200 282
"GET /index.php/core/preview.png?file=%2FNextcloud.mp4&c=72f6e7c613018c0fb5424308065057fd&x=72&y=72&forceIcon=0 HTTP/1.1" 404 2
"GET /index.php/core/preview.png?file=%2FNextcloud+Manual.pdf&c=7cba63cf3e039c046b9bb1377f3cf1eb&x=72&y=72&forceIcon=0 HTTP/1.1" 404 2
"PROPFIND /remote.php/webdav/Photos HTTP/1.1" 207 2010
"GET /index.php/apps/files/ajax/getstoragestats.php?dir=%2FPhotos HTTP/1.1" 200 282
"GET /index.php/apps/gallery/slideshow HTTP/1.1" 200 845
"GET /index.php/apps/gallery/preview/undefined?width=1300&height=1300&c=6abb868b2893c311bf53af0081b9b28e&requesttoken=HQSsKOc7uB1XjkT1D%2Bw%2BET%2B2RPpEcfYXlECDkbYlAfA%3D%3AVzXUaqVUyTZvu3e7Q5kNU32ODr4RAcV9uxbFwuVoTsI%3D HTTP/1.1" 404 101
"GET /index.php/apps/gallery/preview/undefined?width=1300&height=1300&c=94f174493e4cf040efc81dd032376e6d&requesttoken=HQSsKOc7uB1XjkT1D%2Bw%2BET%2B2RPpEcfYXlECDkbYlAfA%3D%3AVzXUaqVUyTZvu3e7Q5kNU32ODr4RAcV9uxbFwuVoTsI%3D HTTP/1.1" 404 101
"PROPFIND /remote.php/webdav/Photos HTTP/1.1" 207 2010
"GET /index.php/apps/files/ajax/getstoragestats.php?dir=%2FPhotos HTTP/1.1" 200 282
"GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 509
"GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 509