HTML5 uncaught typeError: cannot read property 'toLowerCase' of null

Hi everyone

It’s my first time at packaging for HTML5 and I’ve read a lot of guides and answers around the web before posting here, like [Html5, Building on Windows][1], [guide1][2], etc…

When I package the project my Logs gives me no errors or warnings but as you can see [here ( project website link)][3] I get this error:

HTML5 uncaught typeError: cannot read property ‘toLowerCase’ of null

on my Web Host i loaded these files

220532-mobile-test-001.png

and I avoided to load these ones

220533-mobile-test-noload-001.png

I’ve create a Blank Blueprints project with these settings :
Mobile / Tablet
Scalable 2D or 3D
No Starter Content

PROJECT SETTINGS
-Packaging
Build Configuration: Shipping Client
[checked] :Full Rebuil, For Distribution, Use Pak File, Share Material Shader Code, Shared Material Native Libraries, Cook only map, Create compressed cooked packages, Include prerequisites installer

PLATFORMS
-HTML5

please help me to fix this problem.
Thank you

This error seems to be coming from the main html file from this line:

					// After enabling Content-Encoding: gzip, make sure that the appropriate MIME type is being used for the asset, i.e. the MIME
					// type should be that of the uncompressed asset, and not the MIME type of the compression method that was used.
					if (xhr.getResponseHeader('Content-Type').toLowerCase().indexOf('zip') != -1) {

There “xhr.getResponseHeader(‘Content-Type’)” is returning null. Try changing the if statement to

					if (xhr.getResponseHeader('Content-Type') && xhr.getResponseHeader('Content-Type').toLowerCase().indexOf('zip') != -1) {

Does that avoid the issue?

Another way to fix this is to adjust http://fbusetto.com/ web server to serve content with the “Content-Type” header set - it looks like the bug is that the web server is serving the files without a Content-Type, and the .html file doesn’t expect that this could be happening at all, but expects that web servers tell the Content-Type.