Edited Task: Unable to set Registry value (empty) on FileVersionPrependRegSz [357]

Hello,

i am trying to configure a FileVersionPrependRegSz on Update level rule with the next values.
I need to query default value of registry key, so i left empty the text box [Registry Value]. The problem is that the [Ok] button only became active if i enter anything in [Registry Value].

Actually, i workaround this by saving a rule on disk, editing manually with text editor and loading. With this method i can use an empty value.

Is posible to fix that situation?

THANKS!!!