Error by choosing folder with iPhone APP

Please help us by providing the following info.

Steps to reproduce
1. Start APP Owncloud
2. Login successful
3. I can see all folder in the root directory
4. by choosing a folder i get the error message, that i have to check if the folder exists

Expected behaviour
Tell us what should happen

Actual behaviour
Tell us what happens instead

Mobile client configuration
Client OS (iOS, Android, ...): iOS

Server configuration
Operating system:
Web server: apache
Database: mysql
PHP version: 5.6
ownCloud version (see ownCloud admin page): 9.1.0
Updated from an older ownCloud or fresh install: fresh
ownCloud log (data/owncloud.log):

Special configurations (external storage, external authentication, reverse proxy, server-side-encryption):

Could you open an issue in https://github.com/owncloud/ios with your description, please? Thanks!