Error Message Appearing

My students are getting white boxes in the middle of their screens when they try to go to the next activity. The box just gives them two options - Try Again or Start Lesson. When they click on Try again it takes them back to same place. Start Lesson has them repeat lesson they just completed. This has been occurring for two days. It is not our system as no other website has issues. Please give me suggustions to fix.

I’m having the same problem on the Professional Course. It says to check my internet connection but that doesn’t help anything. It seems to be the audio lesson that’s stalling because the typing lessons work fine.