or one of its dependencies, requires a later version of the .NET Framework than the one specified in the project. You can ...

'%1', or one of its dependencies, requires a later version of the .NET Framework than the one specified in the project.
You can change the .NET Framework target by clicking Properties on the Project menu and then selecting a new target in the '.NET Framework' dropdown box. (In Visual Basic, this is located on the Compile tab by clicking the "Advanced Compiler Options..." button.)
Do you still want to add a reference to '%1' in the project?