Hi,
We recently updated from Meteor 1.5.1 to 1.6.1.1. We encountered the same problem raisedhere. The problem was when Meteor updated their code forWebAppInternals.getBoilerplate to return astream as opposed tostring before.

So we temporarily fixed it by converting the stream to string & passing the string tohtml minifier used as below:

const meteorHtml = WebAppInternals.getBoilerplate(stepResults.req, WebApp.defaultArch);
let actualHTML = '';
meteorHtml.stream.on('data', (chunk) => {
actualHTML += chunk.toString();
});
meteorHtml.stream.on('end', () => {
stepResults.html = htmlMinifier.minify(actualHTML, {
removeScriptTypeAttributes: true,
removeStyleLinkTypeAttributes: true,
collapseWhitespace: true,
});
But after doing this, when we hit the application we get a blank page with console printed that we had put after the createRouter call finishes.

Can someone please help understanding what might be the cause of it or some pointers to debug the issue?