I have been trying to use AppCache in my Angular CLI project, and have been following all AppCache guides which seem pretty straight forward, but I keep getting this error:
My manifest.appcache file is in the same directory as my index.html.
manifest.appcache:
I have also tried referencing the manifest.appcache file through an iframe tag, but i also get an error by doing that saying that the it cannot find that iframe-inject-appcache-manifest.html file either. I'm am not sure if it is possible to implement AppCache on angular 4
The fact that your browser receives a 404 seems to point to a web server configuration problem more than an Angular specific issue.
You may want to dig in for angular cli's server configuration or (if it is not exposed) go for a standard alternative (Apache/nginx/express...)
Also note that the manifest is supposed to be served by your web server with the mime type: text/cache-manifest, though this article says it is not mandatory anymore.