Hosting Storyline Courses on SharePoint Online

Hi,  I've uploaded SL360 to SharePoint for years, so perhaps I'm missing an important detail about your issue but here's how I do it:

• In SL360, publish the course to 'Web' to a folder on your C Drive.

SL360 packages the course in one folder ending with "- storyline output"

• Right click on that main folder and select Copy
• Paste the folder into a SharePoint Library - you can only do this via Windows Explorer, so you'll need to have the SharePoint library accessible there.  If you try to upload the folder into the SharePoint browser, you'll lose files.
• If you have 'Checking Out' required for that library, you'll need to check in all the files (look inside all the sub-folders, too) Personally, I remove the requirement to check out/in documents to avoid this extra work, as there's typically 100+ files.
• You're ready to send the SharePoint link to learners via email (or post it to a List, Word document, etc.). 

The link to open the course is for the file labeled "story", or "story.html, or "story.html5" found in the first level of the main folder.  In the SharePoint browser, click the "..." and copy the URL provided.

Note: I do all my SP work in IE, as it's buggy using Chrome. I've never changed file extensions and have always had courses open and work as expected.  Learners can use Chrome to open the course, though.  I'm not sure about other browsers.

I hope this helps :-)