Most of the servers supporting the OCC are returning 503 errors:
503 Service Unavailable
No server is available to handle this request.
Usually [Insert naff Organisation Name here] has not paid its bills, renewed its security certificates or third party agreements, checked its server logs for overflow or even just let the servers or network equipment crash.
Xara only offer 98% availability of its on-line services, which are provided by Magix. That's as much as 15 hours downtime a month.

I would access the OCC > Stock Images > Search: anything and then click on Powered by Pixabay link.
Pixabay then advises not to use IE11.
@Xara - there will be a time in the near future when Pixabay will block you fully.

Acorn