Creating webhooks not working anymore since 1 day!

in Development
Since yesterday your API is responding with an error message when trying to add webhooks.
I am not allowed to add webhooks for the itemgroup 'invoices' anymore. Itemgroup 'orders' however does work.
The error message is :
{"error": {"code": 403,"method": "CREATE","request": "/nl/webhooks.json","message": "The server understood the request, but is refusing to fulfill it."}}
My request message POSTed to https://api.webshopapp.com/nl/webhooks.json is:
{"Webhook": {"IsActive": true,"ItemGroup": "invoices","ItemAction": "created","Format": "json","Address": "https://myhost/someapi/invoice"}}
Please fix asap, we cannot handle new seoshop app connections right now!
2 comments
Thank, we have received your ticket about this and when put under my attention, resolved quickly. It should be possible to create these webhooks again.
If not, please let me know through the ticket I just sent you. Thanks!