The reason of the problem might be that you reference to another module/control that has been built using the old .dll files. The controls must be placed in those pages that throw the error.
First of all you should delete the references of your controls / modules / and add the new ones from the bin
folder of your SitefinityWebApp
project. After that you have to build your custom modules / or controls /, delete the old references from theSitefinityWebApp
project and add the newly built dlls of your updated modules and controls. Finally you have to build the entire solution and the problem should be fixed.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items