Diagnosis
The RFC destination required to connect to External Tax System forcountry &V1& has not been maintained.

Procedure
In Customizing for the TTE,
Choose Transaction Tax Engine -> Tax Maintenance Settings ->Country-specific settings
Choose &V1&
Choose Assign External Tax Types and MaintainJurisdiction Levels
Check and if necessary maintain the external tax system in CountryAttributes.
Save your entries.
Choose Define External Tax System
Choose the relevant External Tax System and display the RFC destination
Choose SM59 to view the RFC Destination of the relevant tax system
Choose Technical Settings.
Check and, if necessary, adjust the activation type to Registered ServerProgram.