Collab (as well as Cloud Diagnostics) has been experiencing service disruption this weekend due to our authorization service experiencing technical difficulties. We're extremely sorry for the work lost during this outage and are in the middle of a postmortem to figure out the exact cause and what can be done to better shield our service from this kind of disruption in the future. There will be more updates about the cause of this outage coming soon. The issue has since been resolved and Collab should be back in working order. Please let us know if you are still experiencing any issues connecting to Collab or performing publishes/updates. In the future, please consult https://status.cloud.unity3d.com/ to check if any of our services are experiencing any issues. And sorry again for the inconvenience.