title: Error: Could not load log4net assembly
body: <p>I am looking to solve this error: </p>
  
  <blockquote>
    <p>Could not load file or assembly 'log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692fbea5521e1304' or one of its dependencies. The system cannot find the file specified." This error is located in the web.config file.</p>
  </blockquote>
  
  <p>When I copy log4net.dll to the bin directory of my webapp, I get a </p>
  
  <blockquote>
    <p>Could not load file or assembly 'log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692fbea5521e1304' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference.</p>
  </blockquote>
  
  <p>This error also occurs in the web.config file.</p>
  
  <p>It's easy enough to change the version and the public key token to match the file so that the assembly loads correctly. When I do that, my website runs perfectly, except for when a <code>reportViewer</code> object is initialized. Then it throws the original error at the reportViewer tag, not the web.config. </p>
  
  <p>My hypothesis is that if I install the requested version of <code>log4net.dll</code>, my problems will be solved. But I have no clue which file that it, or where to find it. I've checked the obvious by downloading log4net 1.2.10 and trying out every dll in the download. </p>
  
  <p>I should mention that the website runs without issues on my development machine, but not when published to my server. </p>
  
  <p>I'm running an asp.net website, .NET 4.0, IIS 7, on a Server 2008 R2 OS. I've installed Crystal Reports 13.0.1 for 64bit (my machine is 64bit).</p>
  
  <p>How can I resolve this issue?</p>
  
  <p>EDIT:
  In response to @Kevian's answer, I have made the change to my web.config file. I still get the error where the manifest definition doesn't match the assembly reference. The code that throws this error is:</p>
  
  <pre><code>Line 33:     &lt;CR:CrystalReportViewer ID="CrystalReportViewer1" runat="server"   AutoDataBind="true"
  Line 34:         BestFitPage="True" ToolPanelView="None" /&gt;
  </code></pre>