Could not load file or assembly 'Microsoft.ReportViewer.WebForms'

Question

I am trying to use the report viewer in asp.net and have uploaded my site. However, when my page containing the report viewer is loaded, it shows the following error:

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Answer 1

My trial version of DevExpress had expired. Try renewing it again.

Answer 2

My solution is:

1. Copy dll Microsoft.ReportViewer.WebForms.dll into Bin folder in your project.
2. Remove your reference.
3. Add new reference from bin folder.

I hope this can help.

Answer 3

In order to Run Report Viewer On server with Data from Server

A) Go to Project Property ----> Select Reference ------> Add Reference

1) Import (Microsoft.ReportViewer.Common.dll)-----> (Path "C:\Program Files (x86)\Microsoft Visual Studio 10.0\ReportViewer")

2) Import (Microsoft.ReportViewer.ProcessingObjectModel.dll) -----> (Path "C:\Windows\Assembly\GAC_MSIL\Microsoft.ReportViewer.ProcessingObjectModel")

3) Import (Microsoft.ReportViewer.WebForms.dll)-----> (Path "C:\Program Files (x86)\Microsoft Visual Studio 10.0\ReportViewer")

B) In Above three DLL set its "Local Copy" to True so that while Building Deployment Package it will getcopied to "Bin" folder.

C) Publish the Solution

D) After that Upload all the files along with "Bin" folder with the help of "File Zilla" software to "Web Server".

E) This will install DLL on server hence, client is not required to have "Report Viewer.dll".

This worked for me.

Answer 4

I've installed Microsoft.ReportViewer.2012.Runtime nuget package and problem has been solved without installing ReportViewer.msi or sql feature pack 12

Answer 5

Updating ReportViewer should works. Use below instruction to install updated ReportViewer from Nuget Package Manager console.

Install-Package Microsoft.ReportingServices.ReportViewerControl.WebForms

Just add below assembly reference in your aspx file.

Here, 15.0.0.0 is the version number of the ReportViewerControl.WebForms that was installed in my VS. Please check Reference of the Solution to confirm the version number. No need to add PublicTokens (if multiple installation exists, it may creates trouble again).

Answer 6

I had this error when going from version 10.0.0.0, i.e. "Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />

to version 11.0.0.0, i.e.

"Microsoft.ReportViewer.WebForms, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"

It took a while until I understood that not only the version was changed but also the public token key, as you can see above.