Error when accessing change request in user profile

Reproduction steps:

• Install change request on farm from the extension manager
• Try to access the change request tab in user profile

Expected result:

• the tab displays a live data with the CR of the user

Obtained result:

• a velocity error is displayed starting with:

  Failed to execute the [velocity] macro. Cause: [Cannot invoke "java.util.Collection.contains(Object)" because the return value of "org.xwiki.extension.InstalledExtension.getNamespaces()" is null]. Click on this message for details.