SAP Message CA_TTE634 - TTE Kernel is deactivated; contact system administrator

Diagnosis
The kernel is deactivated due to:
Incorrect settings in the IPC Administrator tool.
or
Database failure during Customizing refresh.

Procedure for System Administration
Check that the flag Enabled is set in the Transaction Tax Enginetab in the IPC Administrator.
Restart the IPC.
If problems persist, contact the support line.