# Manipulate: strange behavior of Manipulator

Bug introduced in 10.2 and fixed in 10.3

Consider this simple code:

Manipulate[n, {n, 1, 5}]


When we evaluate it, we'll get

Now try to click on the little plus sign to expand the controls. Suddenly the slider will jump forward, in this case to value 4.

I'm almost certain that this is bug. Is there something we can do to mitigate this unexpected this behavior? I'm using Mathematica 10.2 64bit on Windows 10.

• Reminiscent of a fixed bug: (82932) – Michael E2 Sep 2 '15 at 23:17
• It's not exactly a fix, but a workaround would be to add Appearance -> "Open" to the definition of your Manipulate variable (i.e. {n, 1, 5, Appearance -> "Open"}), so that the control will start out in the open state. – MarcoB Sep 3 '15 at 3:05
• @MichaelE2 and again, I'd not say it was fixed :-/ mathematica.stackexchange.com/q/90028/5478. From the user side, there is still problem with opening Manipulators, they (I) probably don't care about details :) – Kuba Sep 3 '15 at 6:28
• @Kuba Yes, hence the link. Maybe we can file all under one big bug, "My Mathematica doesn't work." :) – Michael E2 Sep 3 '15 at 11:43
• @MarcoB {n, 1, 5, Appearance -> "Open"} as well as {{n, 1}, 1, 5, Appearance -> "Open"} doesn't work as a workaround for my Mathematica 10.2 on Win10. Did you try it? – Karsten 7. Oct 5 '15 at 16:30