Modification of template Bonsai scripts causing errors

I'm repeatedly running into issues when trying to modify Bonsai scripts.

Issue 1: The Opening of the script throws an error regarding Bonsai.Windows.Input.KeyDown (Bonsai 2.8.5)
Issue 2: Opening the same script throws an error regarding an XML document Namespace prefix 'beh' not defined (Bonsai 2.81)

I ran into the issue when modifying the Standard_oddball.bonsai first and could fix it after reinstalling Bonsai and repeating the setup.cmd step.

Switching over to modify Standard_oddball_slap2.bonsai caused the same issue once again.

It would be helpful to figure out what Bonsai version needs to be run and how the two errors can be avoided.
Anyone else running into the same issues?