Getting various messages, such as:
"Sage 100 cannot connect to the Sage payroll tax service.
Please see the Activity Log.. for details."

"One or more errors occurred.
An error occurred while sending the request.
The underlying connection was closed. An unexpected error occurred on a receive.
Unable to read data from the transport connection. An existing connection was forcibly closed by the remote host.
An existing connection was forcibly closed by the remote host (err/ret=2/0)"

Tax Calc Service Status Check Detail:
"Type: ERROR | Index: Ping | Problem Description: he SPA Tax Service could not be reached from Sage 100. The exception was: One or more errors occurred. One or more errors occurred.."

This was working fine last week.

Of course we're working with the IT company, and have been for several hours. Seems like it has to be a firewall issue, right? We can get the Payroll Status Check to go green most of the time, although sometimes it gives us an error on the Tax Calc Service - but then we run it again and it passes. 

And yes, we have opened a ticket with Sage Support.

Hoping to hear how others may have worked through something like this.