How to solve "MIME type" errors in deployed canisters?

I’ve put in place this set of changes, helpfully recommended by AdamS in the ICP Developer Community Discord:

You’ve set up your URLs wrong.
The assets dir is not a component of your URLs. assets contains static data, and is served from the root, same as generated data does not have dist in the URL.
And then you’ve set a script to be imported from /src , which isn’t included in the assets container at all, and which is superfluous; the bundler converts your JS code to a single file that’s already being loaded in <head> for you.
Delete the <script> tag from the <body> , and change the <link> tag to point to /main.css .

The CSS and embedded image now display correctly but still nothing is functioning. I also tried removing all references to the internet_identity canister since this is not needed in the IC version, and deleted and re-deployed the full set of canisters. It now just gives this one error:

image

This frontend (one of two) is now deployed at https://qb7ig-qiaaa-aaaao-a2h3a-cai.icp0.io/.