The reason for this is that in your custom library project you reference a particular assembly. This assembly is referenced by specific version
. Therefore, you always get to reference a particular version of the assembly. Try setting Specific Version
in the properties window for the Reference to Telerik.Web.UI.dll in VS. Compiling your custom library should now give you version independence, as Telerik.Web.UI.dll is now referenced by name only. Check it out.
the Telerik team