Error in error log for Web Push Notifications

[Scorpions95]

when i clear the cache and cookies of my browser (Mozila fire fox) i suspect the following issue
here is the picture
http://test.kefcheto.eu/ext/dmzx/imageupload/files/6e9b0ee1e5f359fba23916f39f75c5c4.png
@lavigor how can i fix it?

[Scorpions95]

anyone there? @lavigor ?

[lavigor]

@Scorpions95 sorry for the late reply.
I assume this is due to a Mozilla issue, but I'm not exactly sure whether this is the intended behaviour.
Web Push API hasn't been 100% standartized, so this is OK.

No matter what this problem isn't critical and should not affect the general work of the extension.

[Scorpions95]

@lavigor
can this would be from non-cashed mozila firefox?
now u use opera browser can u make this ext to send notify through opera browser?

[lavigor]

@Scorpions95 sorry, I don't have enough testing data for answering about error origin.
Web Push API is still a Working Draft and is subject to possible changes.

Opera browser should be supported: https://caniuse.com/#feat=push-api.

[Scorpions95]

@lavigor
can you try it with opera?

[Scorpions95]

@lavigor can you see this issue
#14