Dirty flag not set when deleting model controls


I think there is a bug in the SDK:

I imported a model which has skeleton and animation contols. After I deleted these controls the “dirty flag” was not set. Which means I cannot save the file.

change something in the model such as the material.

Do you only experience this when you delete Controls or maybe also when you add a control or similar?
Edit: I am working on it
Edit2: See here