Cornerstone LMS rendering course in IE7 as default browser

We have developed course in storyline 2 and we have added one external HTML 5 interaction page in the middle of the course and published HTML 5 SCORM package. We have cornerstone LMS and uploaded course in LMS and assign to the users, but some of the users having issue with the course, when they reached external HTML 5 page is not loading and they cannot advance the course until they not complete the page interaction, so we have discovered the problem that the course render in IE7 as default browser of users (please refer the Screenshot). And we have contact cornerstone and they suggested us to set cornerstone default browser settings as “NONE” we have changed all suggested cornerstone settings but still we are facing the same issue. So can any buddy help us how to resolves this issue.