Thanks for the file. The template objects in this scene are modified, probably because they were merged from other scenes. Please, try this:
- Be sure there are not Forest objects using "Template" (as Forest006). Set them temporary to "Disable".
- Open the Layer Manager, and disable "Hide" and "Freeze" checkboxes of the layer "forest_templates"
- Select all "_forest_template" objects from this layer, and delete them.
- Save the scene, reset and reload.
- Select any Forest object and set a Template. The template objects in the layer will be rebuilt, fixing the problem.