Spectrum users in a specific region are unable to login to OneClick. All users outside this region are able to login without issue. The users that are unable to login are all getting the following error:
The user cannot be authenticated. The OneClick Client will be closed. Error message: Remote Host closed connection during handshake.
For this particular issue, the root cause was a network configuration issue in the region where these users were located. The Spectrum traffic was being blocked.
Check the network configuration in the region where the users are located to ensure the Spectrum traffic is not being blocked.
Reference the "Communication Across Firewalls" section of the documentation for the ports Spectrum uses for communication.