FULL PRODUCT VERSION :
java version "1.8.0_92"
Java(TM) SE Runtime Environment (build 1.8.0_92-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.92-b14, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows ver 10.0.10586

A DESCRIPTION OF THE PROBLEM :
I am using JavaFX Scene Builder version 8.2.0 and every time I save the FXML file the scene builder removes imports of my own classes.

Also after adding ControlsFX custom controls library to Scene Builder and adding CheckComboBox control successfully saving then opening the file once again the CheckComboBox custom control dissappears and wasn't recognized.

In summary there is an issue with non JDK imports.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1)Make a new JavaFX FXML Application project in Netbeans IDE.
2)Edit the FXML file in a notepad and add any import to your project and then save the file.
3)Open the FXML file in Scene Builder add any control (ex: Label) then save the file.
4)Open the FXML file once again in notepad and you will find the import to your project was removed.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Any non JDK import (import to you project ) to your project will be removed.

REPRODUCIBILITY :
This bug can be reproduced always.