User can't click next button

Hi, I am having an issue with a user who seems to be having trouble with the next button in a course. This course has been around for a while, is deployed to a large number of people and she seems to be the only one having a problem - she tries to click the next button but nothing happens. I have proxied into her account and everything seems to be working fine - I can't replicate the problem. There is no forced navigation or conditions attached to the next button on this slide. Are there any system issues that anyone knows of that may be causing this? Since no one else seems to be having this issue and I can't replicate it, it looks like something on her system but I'm trying to pinpoint what.