SAP Knowledge Base Article - Public

1670087 - Error when building a solution in VS2010; The type 'CrystalDecisions.Web.CrystalReportViewer' exists...


  • When building a web solution that uses Crystal Reports for Visual Studio 2010 the following error is thrown:

The type 'CrystalDecisions.Web.CrystalReportViewer' exists in both
'c:\WINDOWS\assembly\GAC_MSIL\CrystalDecisions.Web\13.0.2000.0__692fbea5521e1304\CrystalDecisions.Web.dll' and


  • Crystal Reports for Visual Studio 2010
  • VS2010


  • The Source file had a reference to Crystal Reports version 10.5.3700.0 (Crystal Reports Basic for Visual Studio 2008)


  • Ensure that the source file has identical version of assemblies as the web.config:
<%@ Register Assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"
Namespace="CrystalDecisions.Web" TagPrefix="CR" %>

See Also


CR2010 2010 CR4VS2010 CR4VS VS2010 NET2010 Crystal Reports for .NET Framework 4.0 crforvs 13 , KBA , BI-DEV-NET-SDK , .NET SDK / COM SDK , How To


SAP Crystal Reports, developer version for Microsoft Visual Studio