It seems that either saving or loading of the settings fails (you did click on "Save", right?).
Could you give some more info, please:

• Which version of ownCloud are you running?
• Which version of user_sql are you using?
• What's your database backend you try to configure in user_sql?

If you have admin access to your owncloud database, you can check if saving the settings worked correctly by having a look at the table oc_appconfig. There should be settings for the app "user_sql", one of it being "sql_driver_default".

Hi Andreas, yes i click on "Save" after Verify Settings :)

here the infos you need:
OwnCloud Version: ownCloud 9.1.0 (stable)
user_sql Version: SQL user backend 2.3
i configure the user_sql at the Backend from OwnCloud (as Administrator)
mysql Ver 15.1 Distrib 10.0.26-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2 with myphpadmin

and yes, i have fully admin access to the owncloud database. here is a screenshot of the configuration at mysql >> https://i.imgur.com/m9RMbza.png

Hm, looks quite fine to me.
Is this the only domain you serve ownCloud on? If yes, what happens if you duplicate your settings for domain "default"?

I could explain this behaviour if you are accessing your Cloud from another domain or directly using its IP address.

Yes this is only the one server. i have duplicate the login information's to "default" and now without errors, but its no synchronizing (i cant see the Users of the another Database)

Here my owncloud log >> https://i.imgur.com/RS339D8.png
and here is only one user (admin) >> https://i.imgur.com/Ft0R9WX.png

That's really strange. The log doesn't even include information about ownCloud trying to list the users from the user_sql backend.

It's been a while since I did a clean installation of ownCloud, so I'll do that and check if I can reproduce your problem. Beforehand, a few more questions:

• Which distribution and version are you running, it looks like some sort of Debian?
• Did you install ownCloud from the tar archive or from a distribution package?
• You seem to be authenticating against Joomla - which version exactly?

Okay, Thanks for your time!

Here the Infos:
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux
Distributor ID: Debian
Description: Debian GNU/Linux 8.5 (jessie)
Release: 8.5
Codename: jessie

I have install ownCloud via. zip archive from ownCloud Website.

its Joomla! 3.6.2

yesterday i did a clean install of ownCloud and user_sql Plug-in, and i have the same symptoms.

I just did a fresh installation of Debian Jessie, ownCloud 9.1.0, user_sql 2.3 and Joomla 3.6.2. Everything went without problems, my Joomla user is in the list and is able to login.

Here are the settings for user_sql:

I didn't change the settings on the remaining two tabs.

okay, that's strange. maybe its a misconfiguration of my mysql server? can you give me the config of your mysql server? so I can compare it

I did not change the configuration of the sql server. I just created a new local user and selcted "Create database with same name and grant all permissions" in phpMyAdmin.

But my MySql Server ist configured by Plesk. Maybe here are another settings adjusted.

I went over your screenshot of the app configuration again and I think I found your problem: You must activate "Invert Active Value" (I did not bother entering the table for "User Active Column" in the first place)

By the way: If you go through the Joomla docs you'll notice that the column "activation" is meant for a completely different thing: It controls whether activation emails are to be sent!
You want the column "block" and, of course, need to check the "invert active value" box.

hey, so you were right . when I set the field "User active" to "Block" and "Invert active values" , it works now. Thank you.