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, guide1, etc…

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

on my Web Host i loaded these files

and I avoided to load these ones

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

Packaging Build Configuration: Shipping Client

Options 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


Options checked
Compress file during shipping packaging

please help me to fix this problem. Thank you