We have been having problems with assortments not working as expected (products displaying correctly then dissapearing after index rebuild or site restart), so we upgraded to the latest DW 10 (10.8) to see if it could help with our issues and now Enable Assortments in settings gives out an error:
Management API request failed. Trace ID: 00-d68ca6ac24dd536f436747dde9d6d81f-c14ec31b3d5e3e53-00. System.InvalidOperationException: Unable to resolve mapping definitions for source type 'Dynamicweb.Ecommerce.UI.Models.Settings.AssortmentDataModel'.
at Dynamicweb.Extensibility.Mapping.MappingService.Map[TDestination](Object source, Type sourceType)
at Dynamicweb.Extensibility.Mapping.MappingService.Map[TDestination](Object source)
at Dynamicweb.Ecommerce.UI.Commands.Settings.AssortmentSaveCommand.Handle()
at Dynamicweb.Management.Api.Controllers.Api.DataController.GetCommandResult(Type commandType, Type queryType, String body)
at Dynamicweb.Management.Api.Controllers.Api.DataController.Post(String command, Object body)
at lambda_method97(Closure, Object)
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()