5.0 to 5.1 - Custom Module no longer functional
We had developed a simple custom module for our Sitefinity 5.0 website in a separate solution leveraging the existing 'Products Module' tutorial located at creating-products-module. This was working perfectly in 5.0 -- Both the CMS administrative section and front-end views were functional and had no errors.
Since choosing to upgrade to 5.1, and following Telerik's suggested guide to upgrading, this custom module is completely broken. The module shows in the back-end System > Modules listing as 'active', but it is not available from the Modules menu so there is no way for the CMS administrators to access it. The System.Config has an entry for the module as being installed as version 220.127.116.11 (which is correct) and there is no "errorMessage" attribute on the corresponding <module> XML element.
Furthermore, the OpenAccess API is broken for the front-end view. When using the custom 'Manager' class to query items from the database is breaks when evaluating the following LINQ-expression: