Learning Module Not Working For All Users

Initial thoughts: 

• Are they using the same systems/builds as the others who have successfully done this?
• Is there *any* different setting *anywhere* with the specific browser that they are using?
• Can you republish this module as SCORM1.2 and have them test it?
• Are they using mobile platforms vs laptops/desktops?

We occasionally have learners who encounter the 1-in-100 situation such as you describe, and in nearly every case that I know of, the problem is either in the browser settings (on the learner's device) or in the person's device connectivity. We are still stuck with using SCORM1.2 so I don't know if there is any meaningful difference between that and 2004 (as far as this type of issue is concerned), but you may want to explore these as avenues of getting around the problems.

The last resort (for us) was to rebuild the troublesome section, and then we added an "escape hatch" that allowed the person to go to the end of the section where they then did the knowledge check required to move to the subsequent section. That may be an option for you too.

Good luck -