With HTML5 projects I get an error when trying to launch game from website


With Chrome I receive: “Uncaught could not load memory initializer UE4Game-HTML5-Shipping.js.mem.gz”
(as I understand, it should work with Chrome when the packaging setting is set to shipping).

With Firefox I receive “Uncaught exception: could not load memory initializer UE4Game-HTML5-Shipping.js.mem.gz”

I tried different values of HeapSize, even tried to use version 4.8 and created multiple projects (then I couldn’t package any projects to HTML5 - always received AutomationToolError, but as far as I know, my emscripten and python path was OK there… anyways, this is another topic…)

I also unpacked my .gz files before uploading them to website and made path corrections in my “Visualisatsioon-HTML5-Shipping.html” file (removed the .gz extensions), it shouldn’t be a hurdle for the game to run? Or Might that be it? The address, where the game should be running is - http://www.unrealestate.ee/HTML5/Visualisatsioon-HTML5-Shipping.html, I believe You can look from the source code if the path corrections doesn’t have any mistake in them.

The reason why I unpacked .gz before uploading to website is that I don’t know how to enable the .gz unpacking in a browser.

In conclusion I have 3 questions:

  1. Why my browsers say in their errors that it is related to UE4Game-HTML5-Shipping.gz if I unpacked the .gz’s before uploading to website. 2. What may cause the error? 3. How do I make my “server” (HTML5LaunchHelper.exe) launch a server in web browser? - Do I even need it? It’s not a multiplayer game.

The version is UE4.9 and uploaded a picture with my files and filenames.

A lot of information - but I hope that You can help me out. Thanks in advance!


Any help, guys?

Hey Prira,

Have you looked over any of the solutions that seemed to have helped others within this AnswerHub? While you’re reading this AnswerHub post, please keep in mind that UE-20600 is currently still backlogged and hopefully it’ll be worked on soon.

Looking forward to hearing back from you, thanks!

Hey, I’ve tried a lot of solutions what You have here but nothing unfortunately worked for me. That’s the reason I made a new ticket. Maybe my approach is a little bit wrong - is this correct that I made a button to my website: if you push the button, it is linked to the Visualisatsioon-HTML5-Shipping.html file. Do I need to do something more or it should work as it is right now?

I couldn’t locate the htaccess file… that was the issue first, but as I found the option to unpack the .gz files first, then update the game onto the webpage - then there is no need to update the htaccess file?


Here is a forum post that should help you set up your htaccess file. Please let us know if you run into any trouble. Make sure that you provide screenshots or full error messages that you run into so that we have all of the information needed to assist you further.

Thank you!


Thanks for info but unfortunately the .htaccess file modifying didn’t help. :frowning: Receive that kind of error (Pic1.png - attached). I used these commands in .htaccess file (Pic2.png and Pic3.png) … also tried to create httpd.conf file like in the link You shared.



We are still looking in to this, please let us know if you make any progress.

Thank you!

What may cause the error:

in Visualisatsioon-HTML5-Shipping.html, line 381:

                            // file location.
                            locateFile : function (name){
                                  return name + ".gz";

this needs to be changed to:

                            // file location.
                            locateFile : function (name){
                                  return name;

We’re not entirely sure how you got [+ “.gz”] in there.

Please keep in mind that the .htaccess file will tell the webserver to send gz files if the browser supports it, this is “outside” of the game’s javascript code. With that being said, you won’t need to write in that code.

Our Developer also noticed that your file was named "htaccess.htaccess’ and it should simply be: “.htaccess”.

How can I create my server within the web browser? Do I even need it?

No, you do not need to upload (HTML5Launcherhelper.exe) - - that executable simply helps you run a “web server” on your development box. Since you’re already uploading it to a web server, it’s not needed.

Our Developer tested this on his local developer box and got it running after removing the [+ ".gz’] in the code above. Please try to remove that and let us know how it goes.

Looking forward to hearing back from you, thanks!

Hi Samantha, I’m over at another answerhub question (How to deploy a HTML5 game on Apache? - Platform & Builds - Unreal Engine Forums) and I just want to inform you that " + “.gz”;" is automatically filled in my html file as well. Removing that part doesnt help me run it on a web server though.


I see that your question has been resolved. Please let us know if you run into any further complications.