Can't upload or create file

I just installated owncloud on a raspberry pi following this guide:
http:// projpi.com/diy-home-projects-with-a-raspberry-pi/pi-owncloud-drop-box-clone/

It was all working before I move my data folder on a external HD!
Now if I try to create a file from webgui or to upload it says it's impossible because it can't find the file!
here my log file: http://pastebin.com/tzAPvm8s
Thank you very much for the help!

Operating system: Raspbian
Web server: apache
Database: mariadb
PHP version: PHP 7.0.8-3ubuntu3
ownCloud version (see ownCloud admin page): 9.1.2
Updated from an older ownCloud or fresh install: fresh install
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):
external storage

ownCloud log http://pastebin.com/gzdRGVL8

index.php/settings/integrity/failed:
No errors have been found.

Hi,

you currently can't move the data directory after the installation:

After doing a fresh installation the same still might happen. Then have a look at the following FAQ:

Thanks RealRancor! This link https://manandkeyboard.tk/2014/09/15/owncloud-and-an-external-hard-drive/ found in the github issue helped me!
Just done it before install wizard and all is working!