Hi Marcia,
I was able to reproduce the issue.
Your application refers the Syncfusion 2.0 framework assemblies.
By default our 5.1 beta does not support 1.1 Framework.
If you need to support 1.1 framework please download the v5.1.0.37 and please refer the below documentation that shows clearly the changes between the builds.
http://www.syncfusion.com/Support/user/uploads/Install.pdfKindly try this and let me know if this helps.
Regards,
Kumaresh