firefox webgl unity load build error (chrome/brave is fine)

I am having trouble getting firefox to load up my game - anyone able to help me out - here is my .htaccess file:

# This configuration file should be uploaded to the server as "<Game Folder>/Build/.htaccess"
# This configuration has been tested with Unity 2020.1 builds, hosted on Apache/2.4
# NOTE: "mod_mime" Apache module must be enabled for this configuration to work.

<IfModule mod_mime.c>
# The following lines are required for builds without decompression fallback, compressed with gzip
RemoveType .gz
AddEncoding gzip .gz
AddType application/octet-stream .data.gz
AddType application/wasm .wasm.gz
AddType application/javascript .js.gz
AddType application/octet-stream .symbols.json.gz
# The following lines are required for builds without decompression fallback, compressed with brotli
RemoveType .br
RemoveLanguage .br
AddEncoding br .br
AddType application/octet-stream .data.br
AddType application/wasm .wasm.br
AddType application/javascript .js.br
AddType application/octet-stream .symbols.json.br
# The following line improves loading performance for uncompressed builds
AddType application/wasm .wasm
# Uncomment the following line to improve loading performance for gzip-compressed builds with decompression fallback
AddEncoding gzip .unityweb
# Uncomment the following line to improve loading performance for brotli-compressed builds with decompression fallback
AddEncoding br .unityweb
</IfModule>





and the webpage i am trying to load it on:
https://vaultsgame.com/Launch

the error:
Failed to download file Build/WebGLVaults.data.unityweb

and then i get
Uncaught (in promise) TypeError: e is undefined <---- this one might be related to the first error so I am focusing on that one...

I tried different clearing the browser data/cache, commenting out stuff and retrying and copying that file to the build directory as well. Same issue

Chrome/Brave work without issue.

 

i saw an error about brotli not liking http (requires https) - which my site is using https and it works fine in chrome in brave - but after removing brotli compression - issue is fixed - i then tried gzip compression - and it didnt work (but still worked in chrome/brave) until i had to comment out ' AddEncoding br .unityweb '

tried to do the reverse for brotli - rebuilt - reuploaded - commented out
AddEncoding gzip .unityweb
and uncommented out
AddEncoding br .unityweb

still no dice - same deal - same error pointing to http instead of https instead of the issue....which its a https website so not sure whats up with that...

for now its on gzip compression and working - if anyone wants to test it out and is curious to help figure out what is up with Brotli -
try this location:
https://vaultsgame.com/Staging

 

Hello, I had the same problem and found a solution.

Problem: firefox can't download the "data.br" file but the download works on all other browsers.
But with the Unity link the webgl works on firefox

Solution:
I checked the Unity header and added all headers line by line in my apache config (or in .htacces in webgl project).

And I found what we need to do so that firefox can download it:

<IfModule mod_mime.c>

# ( And I have place here like you all AddEncoding,AddType,RemoveType,..... for Gzip and brotli)


#You need Add :

<FilesMatch "\.data\.br$">
Header set Content-Type: text/html
</FilesMatch>
</IfModule>

 

Thanks @aureliendu3809 that did it. I'm not using Apache so the fix was slightly different for me, but yes, the solution is that the `data.br` file must be served with `Content-Type: text/html`.