title: Simulation in Catia of different versions
body: <p>My simulation is run in the dum kinetics module, the code was written in vb automation in <br> Visual studio 2010 environment. My problem is when I ran the simulation in Catia R18, <br> the process was completely smooth and successful, but when I tried to run it <br> in a different version, like R20 or R21, an error occurs.<br>
  Through the breakpoint, I found out that the error was caused by the failure of acquiring<br> the &quot;Mechanisms&quot; in the product of Catia. Here is the code :</p>
  <pre><code>theMechanism = product1.GetTechnologialObject(&quot;Mechanisms&quot;)
  </code></pre>
  <p>When the breakpoint executes this sentence, variable theMechanism shows &quot;Nothing&quot;.<br>
  The only way I know to solve this problem is run the code again in visual studio 2012 environment, then the simulation works in Catia R20 or R21, but after that you can't run the simulation in Catia R18, if you want to revert back to the version<br> R18, you have to run the code in visual studio 2010.<br>
  Can anyone explain what is the cause of the conflict between versions of Catia and give me a solution for this? Thanks!</p>