RadCloudUpload depends on third party libraries to support all the different Cloud Storage Providers. If you want to use this control to upload files to Amazon S3 cloud, then you should add a reference to the AWSSDK.dll (which is a part of AWS SDK for .NET Extensions) in your application. Similarly uploading files to Windows Azure requires a reference to the Microsoft.WindowsAzure.StorageClient.dll and Everlive requires a reference to the Telerik.Everlive.Sdk.dll.
So if you have not added the reference to the AWSSDK.dll and attempts to upload files to Amazon S3 then uploading will fail with the following error message. "Telerik.Web.UI.RadCloudUpload with ID="ControlID" was unable to find a reference to AWSSDK.dll. Please, make sure that you have added a reference to this assembly in your project."
You can use the Package Management Console in your Visual Studio to add the reference as shown in the following steps.
- In Visual Studio IDE, Take Tools-> Library Package Manager -> Package Manager Console
- In the Prompt type, "Install-Package AWS.Extensions".
- Finally you will get a message "Successfully added 'AWS.Extensions 126.96.36.199' to <ProjectName> and you are done.
The package management tool will add two assemblies - AWSSDK.dll and AWS.SessionProvider.dll.
The first dll is mainly required for the control to work.
Hope this helps,