Error : Maximum request length exceeded

in web.config file
Sol: 

<compilation debug="true" targetFramework="4.5"/>

    <httpRuntime targetFramework="4.5" maxRequestLength="2147483647" executionTimeout="1600" requestLengthDiskThreshold="2147483647"/>

  

    <authentication mode="Forms">

      <forms loginUrl="~/Account/LogOn" timeout="2880"/>

    </authentication>

   

  </system.web>

  <system.webServer>

    <security>

      <requestFiltering>

        <requestLimits maxAllowedContentLength="2147483647"/>

      </requestFiltering>

    </security>

   </system.webServer>

object reference not set to an instance of an object. meaning

Object reference not set to an instance of an object.

Null Reference Exception:

    In simple words this error means that you are trying to use a reference of an object which is "null".
Means, you haven't initialize  it. If you have to use any object you have to initialize it.

                              This is a RUN TIME exception.