ASP.Net and Cryatal Report

There are 2 phases to solve this problem:

Phase 1: Make sure that your .net framework target is correct. (if using vs2008 it should be 3.5, if using vs2010 it should be 4.0 and 2.0 for vs2005)

Phase 2: Check the version of crystal reports you are using in your project/website and make changes accordingly to your web.config



Detailed Solution:

Phase 1:

1. on solution explorer, right click on your project, go to properties -> build
2. set target framework to 4.0 for vs2010 / 3.5 for 2008 / 2.0 for 2005

Phase 2:

1. check the version of crystal reports you are using
2. if you have dropped the crystal reports control on your aspx page, in the source you can see following line on the top:

<%@ Register Assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" Namespace="CrystalDecisions.Web" TagPrefix="CR" %>

Note the version of crystal reports 10.5.3700.0

3. open your web.config file

you will see this code:

<assemblies>
             <add assembly="CrystalDecisions.CrystalReports.Engine, Version=10.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="CrystalDecisions.Shared, Version=10.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="CrystalDecisions.CrystalReports.Engine, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
        <add assembly="CrystalDecisions.ReportSource, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
        <add assembly="CrystalDecisions.Shared, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
        <add assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
        <add assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
      </assemblies></assemblies>

4. just keep the 13.0 version entries in this code, and delete all other entries as follows:

<assemblies>
  
        <add assembly="CrystalDecisions.CrystalReports.Engine, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
        <add assembly="CrystalDecisions.ReportSource, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
        <add assembly="CrystalDecisions.Shared, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
        <add assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
        <add assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" />
      </assemblies>

5. after doing this, try to rebuild or run the project and it will work.

Go in your web.config file and search for these lines:

<add assembly="CrystalDecisions.CrystalReports.Engine, Version=10.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportSource, Version=10.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>

I am sure there are more than one reference for different version, so find the correct version and remove others.

 Hope this will help you

remove one your reference file and also the code