Login as admin user into your ownCloud and access 
http://example.com/index.php/settings/integrity/failed 
paste the results here.

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your ownCloud installation folder

Enabled:
  - activity: 2.1.4
  - files: 1.2.1
  - files_pdfviewer: 0.7.1
  - files_sharing: 0.7.0
  - files_texteditor: 2.0
  - files_trashbin: 0.7.0
  - files_versions: 1.1.0
  - files_videoviewer: 0.1.3
  - firstrunwizard: 1.1
  - gallery: 14.2.0
  - notifications: 0.1.0
  - provisioning_api: 0.3.0
  - templateeditor: 0.1
  - updater: 0.6
Disabled:
  - encryption
  - external
  - files_external
  - user_external
  - user_ldap

If you have access to your command line run e.g.:
sudo -u www-data php occ config:list system
from within your ownCloud installation folder

    "system": {
        "instanceid": "ocmx3c7cr1jw",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "192.168.38.107"
        ],
        "datadirectory": "\/home\/data",
        "overwrite.cli.url": "http:\/\/192.168.38.107",
        "dbtype": "mysql",
        "version": "8.2.5.2",
        "dbname": "doncloud",
        "dbhost": "localhost",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "UTC",
        "installed": true
    }
}

or 

Insert your config.php content here
(Without the database password, passwordsalt and secret)

With access to your command line run e.g.:
sudo -u www-data php occ ldap:show-config
from within your ownCloud installation folder

Without access to your command line download the data/owncloud.db to your local
computer or access your SQL server remotely and run the select query:
SELECT * FROM `oc_appconfig` WHERE `appid` = 'user_ldap';


Eventually replace sensitive data as the name/IP-address of your LDAP server or groups.

Insert your webserver log here

Insert your ownCloud log here

Insert your browser log here, this could for example include:

a) The javascript console log
b) The network log 
c) ...