Hi,

I've been experimenting with ServiceWorker. I added one to an existing site and all worked well.
Then I created a new site and added a service worker there with the same code.
On the new site any call to cache.put() fails with 'DomException: Entry already exists' (which, if it is referring to the key, is obviously erroneous since 'put' overwrites an entry with an existing key without a problem).


The two back-ends are very different - the old one is VS2015/MVC using IIS Express ; the new one is VS2017/.Net Core using kestrel. But this shouldn't be a factor? - it's the same browser and the javascript for the service worker is identical on both.

Any suggestions on what might cause one to fail whilst the other one works ?

Problem is in Chrome and Chrome Canary.....