VERIFIED SOLUTION i

How to check:. The session count has exceeded the license limit and the logon Failed in Doc1 Designer

Check that the number of concurrent users logged into the Doc1 Designer doesn't exceed the the license limit.
In the Desinger, under the Administration - Sessions menu, check how many users are concurrently connected. You may have some user locked in and need to manually highlight their entry and then click the Logout button. 
Another thought is that someone else on the same domain is using using the same license in a different installation. We would not be able to detect alternate installations so you may need to check into that.

To find out how many users you are licensed for, you will need to call Technical Support so they can verify the actual number of licenses.  

Environment Details

 
UPDATED:  May 29, 2018