You can improve the performance of existing Visualforce pages created before Conga Grid version 1.49.61.

To improve Visualforce performance:

1. In Salesforce, click Setup.
2. In the App Setup area, click Develop → Data → Visualforce Pages
3. Find the Visualforce page you want to modify, and click its Edit link.
4. Click the Visualforce Markup tab.
5. Add the following lines of code:

   
   
   

   

6. Click Save.