Hi Enjoy...
You have done everything perfect, but you have set default parameter as your VAT planning parameter. Pls follow the below steps and then try calculating VAT.
* Login as admin
* Go to Domain settings
* Choose your domain
* Change the parameter set id of your user from default to your VAT parameter id
* Then try calculating vat.
This is because OTM checks for Parameter set ID once again when you click calculate provincial VAT which will be default and not your VAT parameter id. So you need to set your VAT parameter set id as default id for your user.
Hope it will clear your doubt...
