You are seeing an error message after clicking "Validate" while configuring AvaTax for NetSuite. It may look like the error below --
An unexpected error has occurred. Please click <ahref=”javascrtip:window.open(‘/app/crm/support/nlcorpsupport.nl?
(0)”>here</a> to notify support and provide your contact information."
This error is caused by using production AvaTax account credentials in a NetSuite sandbox or vice versa. Production NetSuite instances can only use production AvaTax account credentials. NetSuite sandbox instances can only use AvaTax development accounts.
The Service URL must match the account type during validation.
This issue is resolved by entering AvaTax account credentials that match the NetSuite account type.