Closing the lesson can be difficult. Modern browsers are restricting this feature more and more - and how the lesson is launched plays an important role in whether or not it is possible to close it. For example, if the LMS launches the lesson within the page and displays its own exit button, we cannot close the lesson from within. If the LMS launches the lesson in a popup window we may be able to close it.
Here's what you can do. There are two sample lessons that you can upload into your LMS and see if the close button works:http://share.smartbuilder.com/public/support/scorm2004_close1.ziphttp://share.smartbuilder.com/public/support/scorm2004_close2.zip
The 2nd one has a change that may work. If it does, we can send instructions on how to change your lessons so that they work with your LMS.
If neither work, then the best option is not use a close button within the lesson. Instead, you can show some text with instructions for your learner, to either close the browser window, or click on the "exit" or "close" button that your LMS provides (if there is one).
Hope that helps!