Could not load file or assembly 'System.Spatial' or one of its dependencies. The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))

Hi
    How can I solve this problem. Now I cann't run aspx file.
Could not load file or assembly 'System.Spatial' or one of its dependencies. The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG)) Thanks