Please help us by providing the following info. Before posting please also check the pinned "Known issues" threads and make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/
Steps to reproduce
1. Users created in Windows AD - users granted access in folders permissions to access folders.
2. Added folders in "External Storage" in ownCloud and "green" dot appears
2. Used the same user to access owncloud folders from ownCloud server - see version below
3. ownCloud server latest (taken from Bitnami)
4. When accessing files/folders via Desktop application AND any other means (mobile, web browser, Apple device), it says "Error downloading the list of folders from the server - server replied: Service unavailable"
Tell us what should happen
Folders are shown but cannot be accessed/synchronized.
Tell us what happens instead
We receive error message "Error downloading the list of folders from the server - server replied: Service unavailable"
Operating system: Ubuntu 14.04.5 LTS
Web server: Apache/2.4.23
Database: Ver 14.14 Distrib 5.6.31
PHP version: PHP 5.6.24
ownCloud version (see ownCloud admin page): Bitnami ownCloud 9.1.0-0
Updated from an older ownCloud or fresh install: Fresh install
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):
ownCloud log (data/owncloud.log)
Please paste possible errors in the following code block, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808 for more info
Integrity status for oC9+
Login as admin user into your ownCloud and access http://example.com/index.php/settings/integrity/failed paste the results here.