Why does WebClient not work after upgrade to 10.3

Document ID : KB000116723
Last Modified Date : 02/10/2018
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We upgraded to 10.3 yesterday. 
I can navigate in the web client and restful works, but I have no data in the web client. 
No alarms and no devices in the topology. 
OneClick Works. 
this has worked before the upgrade. 
I am using an admin user, that works in OneClick and has all privileges. 
Why does WebClient not work after upgrade to 10.3?
Please ensure that the security string of the user matches the containers.
Additional Information:
About Using Security Communities to Manage User Access to Models and Devices​: