I have problem in my Step 2 Qbank launching by mac (version 10.14.6) in both web and java client I signed in and clicked the "launch", then the loading bar appeared. After it completed, there was nothing but a black background...

The Uworld replied my net connection may not work. In fact, I use school wireless connection, and my classmate can get the Qbank launched under the same connection (he uses windows system).

My Safari browser updated recently and it seems flash player could not be used anymore, I am not sure if my problem related to this.
Does anyone meet the same problem and find the proper solution?