Problem with Nextcloud on Synology

Hope someone can help me with my installation one Synology-NAS:

I installed Nextcloud 14.0.3 on my Synology DS215j with DSM 6.2.1-23824 Update 1.
I used MariaDB10 and PHP7.0 on Apache 2.4 Webserver.

The installation work fine, also the first step after installation, create User and connection to Database.

But when I now try to login, i always get an error:


No matter which browser I user: Safari, Firefox or Chrome

I need help!!!