DOMException: Registration failed - permission denied

I have a web notification script which works fine. However when i was testing in chrome version 43, I get the error "DOMException: Registration failed - permission denied". This error occurs during the subscription stage.

Here's the code snippet which is the usual process of registration

navigator.serviceWorker.register('sw.js').then(function(reg) {
    console.log('[ServiceWorker] Registration Obj', reg);
    reg.pushManager.subscribe({
        userVisibleOnly: true
    }).then(function(sub) {
        //This never executes and catch gets called
        console.log('Subscription successful, Subscription endpoint:', sub.endpoint);
    }).catch(function(error) {
        console.log("Error during subscription ", error);
    });
}).catch(function(error) {
    if (Notification.permission === 'denied') {
        console.warn('Permission for Notifications was denied');
    } else {
        console.error('Unable to subscribe to push.', error);
    }
});

In the above code, the error occurs during the step where i do reg.pushManager.subscribe().

• This doesn't happen in chrome 49.
• This error always occurs on chrome version 43.

[Note] I assumed its a general problem with chrome version 43 but when i checked sites like goroost.com and pushcrew, they seem to be working fine. Only mine is not working