Hi Jessica,
As few of the users already reported that they can access the documentation portal (same with me), I thought to quickly check the status of OutSystems services. As this could be the case that some of the services were partially unavailable in some other region of the globe. ...And, found there was no reported incident. "All Systems Operational".
You can always check the status and, can subscribe to the updates for the service downtime at https://status.outsystems.com/
I believe, it must be some local issue at your ISP end, which were not able to resolve the DNS.
I would always start with the OutSystems status page, and then pinging the domain at the command prompt to ensure it can resolve the address.
Regards,
Swatantra