Hi,
Look in the <runtime section at the bottom of your Web.config file
if it has this:
<dependentAssembly>
<assemblyIdentity name="log4net" publicKeyToken="1b44e1d426115821" />
<bindingRedirect oldVersion="0.0.0.0-1.2.11.0" newVersion="1.2.11.0" />
</dependentAssembly>
replace it with this:
<dependentAssembly>
<assemblyIdentity name="log4net"
publicKeyToken="1b44e1d426115821" />
<bindingRedirect oldVersion="1.2.10.0"
newVersion="1.2.11.0" />
</dependentAssembly>
or if it is missing completely just add it.
Thanks,
Joe