Rendered diff cannot be displayed for object sheet using big velocity script

Reproduction steps:

• Enable Rendered diff in change request administration
• Edit a document with the object editor
• Add a new Help.Applications.Movies.Code.MoviesClass xobject and fill the properties
• Save the changes in a new change request
• Open the diff in that change request and see the rendered diff

Expected result:

• the rendered diff should display the preview of the movie information like displayed in the movie application

Obtained result:

• the rendered diff displays only a warning saying that the script cannot be executed (cf screenshot)