nopCommerce 2.8 not running

Hey guys

I just upgraded our system from nopCommerce 1.9 to the new nopCommerce 2.8. Very exciting - Thanks for so many new features!
But somehow it isn't running??
I did several backups on the way. 2.0, 2.6 and 2.7 are running fine. Only 2.8 doesn't want to work...

When i try to debug the solution seams to be hanging itself at:
_ColumnsThree.cshtml: @Html.Action("CategoryNavigation", "Catalog", new { currentCategoryId = currentCategoryId, currentProductId = currentProductId }).

Thanks for any suggestions and your help!

Cheers, Beat

Do you have any errors in the System Log - nopCommerce administration System -> Log?

It is strange that the system is hanging without any obvious errors.

You will need to debug the action to see where exactly it is hanging. This is the code for the action:

Presentation\Nop.Web\Controllers\CatalogController.cs:

[ChildActionOnly]
        public ActionResult CategoryNavigation(int currentCategoryId, int currentProductId)
        {
            var customerRolesIds = _workContext.CurrentCustomer.CustomerRoles
                .Where(cr => cr.Active).Select(cr => cr.Id).ToList();
            string cacheKey = string.Format(ModelCacheEventConsumer.CATEGORY_NAVIGATION_MODEL_KEY, _workContext.WorkingLanguage.Id, string.Join(",", customerRolesIds));
            var cachedModel = _cacheManager.Get(cacheKey, () => 
                new CategoryNavigationModel()
                {
                    Categories = PrepareCategoryNavigationModel(0).ToList()
                }
            );

            //"CurrentCategoryId" property of "CategoryNavigationModel" object depends on the current category or product.
            //We need to clone the cached model (the updated one should not be cached)
            var model = (CategoryNavigationModel)cachedModel.Clone();
            var currentCategory = _categoryService.GetCategoryById(currentCategoryId);
            if (currentCategory == null && currentProductId > 0)
            {
                var productCategories = _categoryService.GetProductCategoriesByProductId(currentProductId);
                if (productCategories.Count > 0)
                    currentCategory = productCategories[0].Category;
            }
            model.CurrentCategoryId = currentCategory != null ? currentCategory.Id : 0;

            return PartialView(model);
        }