check if web config does not contains one of the assemlies add assembly="CrystalDecisions.CrystalReports.Engine, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.ReportSource, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.Shared, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.Web, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.Enterprise.Framework, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/> <add assembly="CrystalDecisions.Enterprise.InfoStore, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>