The first time I used Unity to package to the Web, I encountered an error message after publishing to IIS:
Unable to parse Build/online-outputweb.framework.js.gz! This can happen if build compression was enabled but web server hosting the content was misconfigured to not serve the file with HTTP Response Header "Content-Encoding: gzip" present. Check browser Console and Devtools Network tab to debug.
Solution: Set Publishing Settings in Project Settings, check Decompression Fallback
