When you run Kartris, you may see an error similar to the following:
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: Unrecognized attribute 'type'.
This is most likely because your web is set in IIS to use ASP.NET version 1.1. It is simple to remedy. First open IIS (you will find this under 'Administrative Tools') and then right click the Kartris web. Look for the ASP.NET tab, and change the ASP.NET version from 1.1xxx to 2.xxxx.
Note that from ASP.NET 2.0 set in IIS handles everything up to ASP.NET 3.5. From 4.0 onwards, you must select ASP.NET 4.0 in IIS.