Only on Firefox “Loading failed for the [removed] with source”

Question

I want to integrate Marketo form with my existing website on yii framework. My code works on all the browsers except Firefox.

Excerpt from my code:

Answer 1

Today I ran into the exact same problem while working on a progressive web app (PWA) page and deleting some cache and service worker data for that page from Firefox. The dev console reported that none of the 4 Javascript files on the page would load anymore. The problem persisted in Safe mode, so it was not an add-on issue. The same script files loaded fine from other web pages on the same website. No amount of clearing the Firefox cache or wiping web page data from Firefox would help, nor would rebooting the Windows 10 PC. Chrome all the time worked fine on the problem page. In the end I did a restore of the entire Firefox profile folder from a day-old backup, and the problem was immediately gone, so it was not a problem with my PWA app. Apparently something in Firefox got corrupted.