What are some best practices for uploaded an HTML5 packaged game onto a website? I can get mine to run with the local server but once I upload the files to my website, I get a download failed error.
You can try to uncompress the files and edit the HTML to not use the .gz files.
Also, in my own expierence with HTML5, there is a issue causing a Syntax error, returning ILLEGAL token.
To fix this I had to experiment with the .htaccess file as the documanted suggestions aren’t sufficient.
In the end I ended up using a .htaccess of some random community board that had a lot in it, fixing the SyntaxError. But I need more time to narrow down what did the trick in the .htaccess.
Look at this page: https://answers.unrealengine.com/questions/296709/html5chrome-syntaxerrorunexpected-token-illegal.html
It helped me a lot to get in the right direction 
you have to verify links on your files compressed take a look at:
http://ligartarchitects.com/archviz/
How would I go about verifying the links?
Yes I would also like to know - how do you verify links, and uncompress the .gz files?
I am a complete noob in this.
Thanks,
Pavel
Please anyone?
Artidee, I have solved the issue by just using 7zip and uncompressing all the .gz files in the exported html 5 package. Afterwards, by removing all .gz references in the html file. There are exactly 5 of them. There is one where it says “xxxxx” : .gz; and you have to remove everything so its stays “xxxx;.” I don’t know the exact syntax, I am away from my computer. Afterwards you can just upload it to your FTP, rename the xxxx.html to index.html and load up the address in the browser.
This at least worked for me.