This Error give this message…..
This stuff basically happens, if you have correct setup of SBO (I wish you so:)), that between different components of your SBO SDK there are assemblies with different .NET version. Check if you have someold version of SAP BO SDK installed on your machine too. Hope this helps.
add this to your .config file (usually app.config)
<supportedRuntime version=”v4.0″ sku=”.NETFramework,Version=v4.0″/>