Hi Staff,
first of all, I'm so sorry for the stupid question, but where find the version of SilverStripe?
I give a old SilverStripe project and I necessary to fix a little error and continue with some customization.

My problem is:
In the Admin / RelatedContent (TAB) when I unselect the product and click on "save and publich",
the CMS doesn't save my "unselected" checkbox.

I'm sorry, but it's difficult explain. I created a 1 images to explain the error :)
Please... in your experiences... which file i can check for fix the error???

Thank you very much for the consideration :)
G'Day

The problem is in this part of HTML code:

<input id="Form_EditForm_RelatedPages_CheckedList" type="hidden" value=",334,306,306," name="RelatedPages[selected]">
The JS control... don't check the duplicate ID.

Where I can fix this part of code???

Thank you!

FIXED!
The problem is in the file dataobject_manager.js

In the IF condition... "if($container.hasClass('RelationDataObjectManager')) {"
I added the control to check the duplicate string.
And... I changed all OBJ.attr('value', STRING) IN OBJ.val(STRING).

Cheers :)