No basket exist for the current user when checking out in uCommerce
Stupidly this had me going for a while today so this is partly a post to act as a reminder not to do it again but also hopefully to help someone else from doing the same.
A site we are working on was sending the order confirmation email -and processing the rest of the checkout pipeline however it would then error saying that there was no basket for the current user.
The most likely reason for this is that you've set the "Pipeline" on the Payment Method selection like this:
To fix the issue, just clear the Pipeline value and all should work wonderfully again.
2014-04-15 13:43:02,248  ERROR xxxx.www.Controllers.CheckoutController - System.ArgumentException: No basket exist for the current user. at UCommerce.Transactions.TransactionLibraryInternal.Checkout() at Castle.Proxies.Invocations.TransactionLibraryInternal_Checkout.InvokeMethodOnTarget() at Castle.DynamicProxy.AbstractInvocation.Proceed() at UCommerce.Infrastructure.Interceptor.ExceptionLoggingInterceptor.Intercept(IInvocation invocation) at Castle.DynamicProxy.AbstractInvocation.Proceed() at Castle.Proxies.TransactionLibraryInternalProxy.Checkout() at xxxx.www.Controllers.CheckoutController.BillingInformation(BillingInformationViewModel data) in d:\xxxx\www\Controllers\CheckoutController.cs:line 612