On my Windows Server 2012 R2 Files Server, I created a share named "Ventes" on E:\Ventes.
On my OwnCloud, I configured an external storage with OC Credentials (LDAP MS AD 2012R2). I entered IP of files server (10.33.10.26), share name (Ventes), domain name (micrologic2010) and it's displayed a red square.
The only way that I found to make this working is to create a share directly on drive E and enter an "Remote Subfolder" pointing on folder Ventes. With this way, I can access the folder Ventes and all is working.
I test with my older files server (windows server 2008 R2) and I don't have this problem.
Server configuration
Operating system:Ubuntu 16.04.1 LTS
Web server:Apache 2.4.18
Database:MySQL 5.7.15
PHP version:7.0.8
ownCloud version (see ownCloud admin page):9.1.1
Updated from an older ownCloud or fresh install:fresh
Screenshot of the external storage config : https://drive.google.com/file/d/0B0F9rbBh9vCUQ01oTG9zeGRRbXc/view?usp=sharing
OwnCloud Logs file : https://drive.google.com/file/d/0B0F9rbBh9vCUZ1ZmRzRvQjd4cm8/view?usp=sharing
Integrity status for oC9+
No errors have been found.