In Microsoft Dynamics CRM Online 2015 Update 1 (v7.1), a new form renderer was built to provide better performance. With this, forms load significantly faster and more efficiently. The new renderer is based on previous generations and has the same functionality and behavior. However there are some things that admins and developers need to do to ensure full compatibility when upgrading.

What changed?

All the changes have been focused on how the form load process can be optimized. There are 2 main changes that have been made: loading process of the form, and handling of cache.

In terms of loading process, we have parallelized as many operations as possible to eliminate time wasted because the browser is idle. We increased the content that’s cached, moved rendering processes partially to server-side, and optimized the initialization of controls.

Form load used to be a very linear process. Since the new form renderer is more parallelized, the rendering engine now constructs the form and XRM model first and binds the data whenever the server responds. The diagram below is a rough approximation of the differences between the 2 rendering engines and may not reflect the exact changes.

legacy form rendering old and new


Change/Revert Settings

  1. Log in to MS CRM.
  2. Go to Settings -> System Settings -> Administration tab.legacy form rendering change settings
  3. Click -> System Settings tab.
  4. Select General tab.legacy form rendering system settings
  5. Scroll down (End of the Screen).
  6. Select Yes for “Use legacy form rendering” as shown in the images below.



  • This is a temporary measure, as this functionality is expected to be removed by Microsoft in the next CRM release. All the more reason to update any broken script immediately to avoid problems in the future.
  • The technical updates in the Spring 2015 Update 1, including faster loading pages, incorporate a backup plan for those scripts, solutions and customizations that error out during loading process