Add a page such as "Chad's Test Page" to a space. Alter it so that only you can view/edit this page.
Add a child page to this, called.. say.. "Testing Page". Try to alter the permissions on this page, and you get

"permissionsTable is not defined" in a javascript popup.

I've selected 2.9.1 as an affected version, as someone in CONF-10717 said it was. I'm personally testing on 2.10.1.

This is a pretty critical bug for us, but feel free to mark it down. We are doing a thorough evaluation of how far we can lock things down, and this is an area that is impacting us.

Thanks,

Chad