RDLC Report Error: ReportViewer is ambiguous in the namespace Microsoft.Reporting.WebForms

Hi maideen,

1. This happens mostly when you add the same reference twice. Can you ploease confirm the references you added are not repeated.

2. Go to your Web.Config file and check the <assemblies> you may find two assemblies with the same PublicKeyToken but different Version. If found remove one that does not match with the Version Register in the page.

Ex:

<assemblies>
  <add assembly="Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
  <add assembly="Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
</assemblies>