Weird! I can reproduce this. To be clear, its the "Add smartcard support" button that disapears and its not just that but Boxes switches the view away to first page of properties.

(In reply to comment #1)
> Weird! I can reproduce this. To be clear, its the "Add smartcard support"
> button that disapears and its not just that but Boxes switches the view away to
> first page of properties.

At least the last bit is likely connected to refreshing of properties since the same happens if you add/remove a USB device.

The secondary issue I mentioned in comment#1 ("Boxes switches the view away to first page of properties.") has at least been resolved by this patch in git master now:

commit: 56c17f738ffb00687c0030c274370798e8453c9b

    properties: Correctly restore notebook page
    
    We were not actually restoring to the current page after refresh of
    properties due to name clash of 'page' property with a local variable.
    This patches fixes the issue by use of 'this' keyword.

Seems with the redesign of properties view, this is no longer reproducible.

(In reply to Zeeshan Ali (Khattak) from comment #4)
> Seems with the redesign of properties view, this is no longer reproducible.

Actually, no! that is the secondary issue that was fixed by commit 56c17 as I already mentioned in comment#3.

However, I wonder what we want to do here? The row dissapearing was very much intentional since if VM doesn't have the support, we provide an easy way to add it but once it's added, do we really need a way to remove it?

If so, I can change this to a toggle.

If it was intentional, lets leave it alone