Xfinity Email Error 10A - Unable to Access Mailbox on Multiple Computers

Starting a few hours ago, we have been unable to access Xfinity Email. Authentication to the Xfinity account completes successfully, but attempting to launch the mailbox immediately redirects to the Xfinity webmail error page displaying “Please Try Again Shortly - Something Went Wrong - Error 10A.”

I initially suspected a client/browser compatibility issue because the computer normally used for this account is an older Windows 7 system. However, I reproduced the exact same Error 10A using the same account on a completely separate, modern Windows PC, which strongly suggests this is not isolated to the original OS, browser, cache, or local machine.

Troubleshooting already performed:

• Cleared browser cache/cookies/site data
• Signed completely out and re-authenticated
• Restarted the original system
• Reproduced the failure from a separate PC/browser environment
• Xfinity account authentication itself is successful

The failure appears to occur after authentication, during initialization/loading of the Xfinity Connect mailbox/webmail application. This makes me wonder if there is an issue with the mailbox backend, account/mailbox provisioning, session/token handoff to Connect, or another server-side dependency.

Is anyone else currently receiving Error 10A?

If Xfinity Support sees this, could someone please check the mailbox provisioning/status and server-side logs for the failed Connect initialization, rather than just the account login status?