Web3 seems to fail after downloading a DApp

This was reported by a user in Discord:

Hey, for learning and testing, I uploaded pizza dapp files, but web3 seems to fail. do I miss steps to upload a superblocks created dapp? The contract is on Ropsten. I probably need to import app.js and app. css in html?

The Download DApp is expected to work on its own. However, this could have been related to a bug first reported on GitHub Issues here: Downloaded dapp set to external network won’t work

The problem was that the downloaded dapp would include code which would (re)set web3 to a bad state. The issue has been fixed since version 1.7.1: Superblocks Lab - New 1.7.1 release

Specifically about the provided templates, there is still an open issue about web3.eth.accounts calls not working as they used to, likely due to changes to MetaMask (See also: Issue with Metamask accounts request).
More information can be found here: Downloaded dapp calling eth accounts won’t work (Pizza)