It is possible for *some* layers/sublayers to be in Outline mode while others are in Preview mode. 

Check the eyeball icon... if it's got a solid iris, it's in Preview mode.. if the iris is vacant, then it's in Outline mode.

[![enter image description here][1]][1]

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Toggling the `View Menu` for Preview/Outline will **not** toggle sublayers. Sublayers will stay in the mode they are currently in. 

Toggling the `View menu` item **only toggles main layers**. It doesn't even toggle objects on a layer. The menu only sees top level layers, that's all.

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To toggle *individual* layers/sublayers between Preview/Outline modes, simply hold the <kbd>Command/Ctrl</kbd> key and click the eyeball icon in the **Layers Panel**.


  [1]: https://i.sstatic.net/DiRSL.png