Courses Freezing in All Formats (Review, pilot environment, live environment)

Hello everyone,

I currently have a ticket in with Articulate and they are investigating my issue, but I wanted to see if anyone has ever experienced a similar issue. 

We create 3 hour+ courses from recordings of live classes, using Storyline. There has never been any issues reported in the past, but suddenly a select number of reviewers and learners are unable to get our classes to go past the first few slides, no matter what environment the course is published in. Has anyone ever had this issue? We suspect file size or video size is at play, but have never had any issues and don't want to go redoing all 100 courses currently published if there is a more simple solution.

Thank you.