Hi Bhanu,
Please, make sure that you have the tax types mapped in the same dataset as the client that you are using to run the tool. For instance, if you are running the tool in client 200, the dataset 200 should contain the mapping for the tax types.
Also, SAP has released note 2046535, which corrects an issue that may happen with table BTXTAX, but it also cointains a correction for the error messages. Now the error messages should say "It was not possible to insert entry <entry> in table <table>.
Best Regards,
Felipe.