"Value cannot be null." error occurs after upgrading from 1.30 to 1.90

Following error occurs when clicking hyper links on home page "Categories" and "Manufacturers" sections and on "Sitemap" page after upgrading from 1.30 to 1.90.


[ArgumentNullException: Value cannot be null.
Parameter name: type]
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +9643414
   System.Activator.CreateInstance(Type type) +6
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetTaxRate(ProductVariant productVariant, Int32 taxClassId, Customer customer, String& error) +532
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetPrice(ProductVariant productVariant, Int32 taxClassId, Decimal price, Boolean includingTax, Customer customer, Boolean priceIncludesTax, Decimal& taxRate, String& error) +89
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetPrice(ProductVariant productVariant, Decimal price, Boolean includingTax, Customer customer, Decimal& taxRate, String& error) +145
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetPrice(ProductVariant productVariant, Decimal price, Customer customer, Decimal& taxRate, String& error) +189
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetPrice(ProductVariant productVariant, Decimal price, Decimal& taxRate, String& error) +131
   NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.GetPrice(ProductVariant productVariant, Decimal price, Decimal& taxRate) +105
   NopSolutions.NopCommerce.Web.Modules.ProductPrice2Control.BindData() +886
   NopSolutions.NopCommerce.Web.Modules.ProductPrice2Control.OnPreRender(EventArgs e) +47
   System.Web.UI.Control.PreRenderRecursiveInternal() +103
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Control.PreRenderRecursiveInternal() +175
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2496


Anyone has an idea? Please help.

Thanks,
~Saliya R.

When I debug the code I found that NopSolutions.NopCommerce.BusinessLogic.Tax.TaxService.ActiveTaxProvider returns 8 for the taxProviderId but I compared that value in [dbo].[Nop_Setting] table with 1.9 release data and it was 6. So I believe there is an error in your upgrade script. It has missed to update this value from 8 to 6. Please correct me if i'm wrong. Waiting for your response to continue this process.

Verify the setting value using following query.

SELECT *
FROM [dbo].[Nop_Setting]
where SettingID = 96

Thanks.
~Saliya R.

I'm now getting another error when checking out a product. Occurs the same error going from "Shipping to Payment". This time it fires in NopSolutions.NopCommerce.BusinessLogic.Payment.GetAdditionalHandlingFee, for the class name "NopSolutions.NopCommerce.Payment.Methods.VirtualMerchant.VirtualMerchantPaymentProcessor, Nop.Payment.VirtualMerchant". Waiting for your help.

Thanks,
~Saliya R.