I have a PWA (http://app.turath.io) that loads a JSON file from another subdomain. This works fine in Safari iOS, but it fails once I add the site to homescreen. The error message: > Fetch API cannot load https://files.turath.io/data.json due to access control checks. > Failed to load resource: Preflight response is not successful This only recently broke.
I have a similar situation Very important to fix
Note: I updated the service worker to ignore this fetch, and that *seems* to have fixed the issue. If so, the bug is with the sw's proxying. The change I made to the service worker: self.addEventListener('fetch', e => { + if (e.request.url === 'https://files.turath.io/data.json') + return; e.respondWith(caches.match(e.request).then(r => r || fetch(e.request))); });
<rdar://problem/65110679>