TermIt

FWIW, I think the problem is not on the server side. I did a bit of testing around and I think it is due to browser caching. The empty page is caused by server returning 404 Not Found for requests for JS (and sometimes also CSS) bundles. Therefore, the application does not start on client and the screen remains blank.

But when I checked, it seems that the browser is asking for the wrong files. For example, I had an error when it asked for file main.32936da8.js, however, subsequent refresh yielded a request for file main.d6824134.js, which was loaded successfully.

So my theory is as follows: the browser has cached index.html, the page loads and JS bundle referenced by this cached HTML file is requested from the server. However, in the meantime, the UI has been rebuilt by Jenkins, so the file is no longer valid (the numbers in the file name are apparently some sort of hash), resulting in a 404. Refresh reloads the cached index.html and the correct JS is requested this time.

I think it's confirmed, I just checked. Build #524 produced file main.32936da8.js (see the log at https://kbss.felk.cvut.cz/jenkins/view/18OPPPR/job/termitui-dev/524/console at the end), while build #525 produced file main.d6824134.js (https://kbss.felk.cvut.cz/jenkins/view/18OPPPR/job/termitui-dev/525/console). This is consistent with my theory.

Add a message to index.html to show to the user to refresh the page.

This SO answer could help to prevent caching of the index.html in client browsers for development deployments: https://stackoverflow.com/a/2068407/4929038