Tax Connect error "System.Net.WebException"

I have a user that gets an odd error via TaxConnect.

After calculating the taxes, and viewing the Tax Connect Results yeilds an incomplete message window (note the blank RefersTo and Details fields):

Recalculating the taxes again often fixes it, sometimes taking more than 1 try.

Is this a connection issue between the App server and Avalera?

I did the Test Connection in Company Config, and it tests okay.


I just ran the Test Connection again and got (after about a minute of waiting):


Checked with, and they report no issues.

Anything on my side of the firewall to check?

Works for me, obvious question is… your internet working from the Epicor server?

No generic internet issues (that I see).

The results of running the connection test shows the failures are intermittent.

I’m located remotely from the servers and use RDC to connect to them (through the internet, not our LAN). I’v had no issues with the RDC connection.

Just got 2 failures, then 2 successes, then another failure.

Looks like you have a node somewhere in your path between you and them that is dropping stuff…
Run a ping -t avalaraIPAddress > file.txt for like 10 minutes
and see what your dropped packet rate is.

Also check the internal messages, see if they reveal anything more:

SELECT * FROM Erp.TaxSvcConfig;
SELECT * FROM Erp.TaxSvcHead;
SELECT * FROM Erp.TaxSvcDetail;
SELECT * FROM ERp.TaxSvcMessages;

The internal messages is what had me looking at this in the first place. They provide no more details than:


Did the ping yield anything?

Ping returns the IP address (So DNS has a value), but no response.

I figured they disabled ping to reduce the chance of a DDOS attack

ah… bummer

I’ve punted this to our network people. I’ll post what they find (if anything).

1 Like

Here’s an update and something that appears to correlate…

If I ping it always times out. But it shows the IP address of that endpoint.

If I repeatedly ping it, I usually get
But I occasionally get a

Seems that If I perform the Test Connection (in Company Config) and get a the Tax Connect timeout message, the IP showed by the ping cmd is

And isn’t the name to IP resolution done by DNS? Is it strange to see the IP for a URL to change so quickly?