Could not load file or assembly crdb_adoplus.dll in WinApplication

when you received this kind of error:

"Could not load file or assembly 'file:///C:\Program Files\SAP BusinessObjects\Crystal Reports for .NET Framework 4.0\Common\SAP BusinessObjects Enterprise XI 4.0\win32_x86\dotnet1\crdb_adoplus.dll' or one of its dependencies. The system cannot find the file specified."

Try to add this to your .config file (usually app.config)

< startup useLegacyV2RuntimeActivationPolicy="true">

< supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>

< /startup>