Cachebust error on upgrade

I am trying to upgrade an app from 5.14.1 to 5.21.4. I opened my existing app, converted in place and addressed all warnings/deprecations and am getting a cachebust error when I try to run locally. I've read the forum suggestions about adding to the index.html but that is not working for me. I have not commited the upgrade as I'd like to test first. Is the new converted app in the same directory? Not sure if I'm editing the correct index.html I am using as custom theme - cosmo. Is that overriding the index.html so that I need to add cachebust elsewhere? Thank you, Tracy
1 answers

In your project directory there should be a folder called theme. There should also be a zip file containing your theme witch you can extract to edit the index.html file. After adding cache bust you should zip the contents again, and make sure it is selected in your project settings.