Html5 not starting on Chrome

Hi, I have this weird problem when trying to launch the html5 version of a course (two, actually, very similar) in Chrome.

The app doesn't start: it shows the first loader on white screen, then the loader on the player background, and nothing else happens: it continues to load but it doesn't show.

The course is made of four scenes: intro + 3 content scenes.

I tried to export them separately (to say: intro + scene 1; intro + scene 2, intro + scene 3) and they work perfectly.

Can you help me?

This is the link:


12 Replies
Ashley Terwilliger

Hi Davide and Andre and welcome to Heroes!

Thanks for sharing the link to your course here - I experienced the same slow loading of your course using Chrome on my desktop, and I wanted to confirm that you were using Safari on the iPad and Chrome on the desktop as detailed here.  

I haven't experienced the slow playback with any other courses I've been testing this week - so I'm curious if you could share the .story file here with us so that we could take a look at publishing it and then running it from a different web server?

Ashley Terwilliger

Hi Andre, 

I need the .story file - which is the file prior to publishing. You can attach it here using the little paper clip icon - and the forums have around a 20 mb limit I think, so if it's too large you could either strip it down to just a few slides which still exhibit the behavior or I can send you directions on how to share the file with me privately that has a larger upload limit. 

André Gottfridsson

Hi again. 

I made a smaller testcourse. It's still big though and I think you need the assets as well as I think there may be something with the sizes when you have a bunch of slides. Here's a link to wetransfer:

The course is made out of one startscreen with some text and then a bunch of identical slides with a video on them. I noticed that if I hade one slide there was no problem at all. If that can be of any help.

The link to the course itself:

Tested in Chrome on a pc. 

Davide Morena

Hi Ashley (and André!),

I'll try to explain my thoughts on the problem.

First of all, my html5 courses always work perfectly on Chrome.

The main difference in this case is videos.

This course contains about 10 videos.

I have 3 other courses with the same structure (but only with 1-2 videos) and they work perfectly.

I made a smaller version, including only three videos, and it works, but it's very slow to load the first slide.

If you send me directions, Ashley, I can send you the .story file (199Mb).

Maybe I can try to re-code the videos? Can you suggest the best specs for that?



Ashley Terwilliger

Hi Andre, 

Thanks for sending along the link to your assets - as you mentioned testing the HTMl5 output seemed to not load. I tested as you mentioned with just one slide - and saw that one behaved as expected. I also tested a version of your course with the initial video, and then a few other videos I had lying around (can't share the videos here - but they were also mp4s and longer anywhere between 5 and 7 minutes) - and that one played as expected using the HTML5 output. It is still a bit of slow loading time, but not anything unexpected based on how Storyline loads content.  There is also a known issue with certain mp4s not playing until they're fully downloaded as described here - so that could be a part of the issue you're running into, especially with the same video on multiple slides. 

Hi Davide,

In addition to what I shared above with Andre, there are a few other reasons why your videos may not play in the published content detailed here.  As far as a particular codec, you may want to use H.264 codec and I typically convert videos using Handbrake.  If you'd like to look into those items first, great - and I'll also send you directions on how you can share your files outside of the forums or you could use a service like Andre did of 

Davide Morena

Hi Ashley,
thank you very much for troubleshooting my issue this quickly and this kindly. I'm sincerely impressed and I love your products even more now.
Your support has been crucial to solve the issue, but let me spend few words that could be useful for future issues like mine.

With your help, I discovered that the problem was the output quality.

If published with custom (full) quality (as I did), the project doesn't run.
Publishing in standard quality the issue was solved.
Of course video quality is worse, but it's definitely acceptable.
I don't know if this has to do with the size of the whole project, or with the size/number of the videos included.
Now everything is perfect - except for viewing on Android, but that's another .story

Thanks again
Davide Morena

Ashley Terwilliger

Hi Davide,

Thanks for the feedback and update on your particular issue. In regards the video quality, I haven't heard of course not running at all when the video quality is published at the highest quality, but it could have to do with the size of the project and the ability of it to play from your web server or LMS. In regards to changing the video compression, it's done automatically in Storyline although a few users have shared that they use this method to change the video output after publishing. Additionally you may want to share your thoughts on video compression as a whole here in the form of a feature request as those go to our product development team for review.