Hi,

I've uploaded my game through Butler (1.5Gb) and have been trying to run it on the browser. I uploaded it as a WebGL zip from Unity. 

I'm getting this error when I try to access the game:

There was a problem loading your project:

Zip contains file that is too large (Build/Build Versions.data.unityweb)

Please try deleting the ZIP file and uploading another one.

Yes. As mentioned in the FAQ, there are other limits than the total size of an archive. And one of them is, to quote:

The size any single extracted file should not be greater than 100MB.

You really ought to shrink the game some anyway, because that's way too much to load into a web browser at once for most people.