Please check if the assembly mentioned in the error is copied locally in the application's Bin folder. The assembly can be copied in the Bin folder through Visual Studio - select the references to Telerik Reporting assemblies and set their CopyLocal to true in the PropertyGrid.
If it is a WebSite project, check where assemblies are loaded from through the WebSite project's Property Pages, and verify it is the Bin folder, not the machine's GAC.
I hope this information helps.
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