[Notes] Json error when synchronizing

Please help us by providing the following info.

Steps to reproduce
1. Installing the app Myownnotes v1.6 or Notes v0.9.0
2. Trying to login to my owncloud server with good IDs

Expected behaviour
I expected it to login and synchronizes my notes with my owncloud server.

Actual behaviour
Error JSON, no synchronization, no login.

Mobile client configuration
Client OS (iOS, Android, ...): Android 6.0
Client version: Myownnotes v1.6 or Notes v0.9.0

Server configuration
Operating system: Debian Jessie
Web server: Nginx
Database: Mariadb
PHP version:7.0
ownCloud version (see ownCloud admin page): 9.1.1
Updated from an older ownCloud or fresh install:fresh install

User was pointed in #owncloud to the following combination which is working now

https://apps.owncloud.com/content/show.php/Notes?content=174554 + https://f-droid.org/repository/browse/?fdid=org.aykit.MyOwnNotes

so marking as solved.