Lexia Tech Note #203010

Blank Screen Because Exposé, Spaces, or Dashboard Triggered

Solution:

If OS X’s Exposé is invoked while Lexia Reading® is open, the program will become unresponsive, displaying only a black screen.

This article deals specifically with Exposé, but similar issues may occur with Spaces (a virtual desktop feature) or the Dashboard. These may also be triggered via a keyboard command or mouse button.

Exposé is a feature in OS X that allows a user to quickly display or hide all open windows. It can be invoked by using either a mouse button, moving the pointer to a screen corner, or by pressing function keys (F9, F10, etc.). Users should use care to not activate Exposé while in a Lexia product.

Apple has set the side buttons on the Mighty Mouse to enable Exposé by default, which makes it very easy to accidentally invoke it. Lexia recommends that the side buttons on the Mighty Mouse not be used to invoke Exposé.

The following examples are taken from OS X version 10.6 (Snow Leopard). Your panel layouts may vary slightly in other versions of OS X.

Disabling Mouse Button Triggers from the Mouse Panel:

  1. Either click the System Preferences icon in the dock, or go to the Apple menu and choose System Preferences.
  2. Click on "Mouse."

  3. Disable any buttons assigned to Exposé, Spaces, or the Dashboard by clicking that button's drop-down menu and choosing "---" as the button assignment.

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Disabling Exposé through its System Preference Panel:

  1. Either click the System Preferences icon in the dock, or go to the Apple menu and choose System Preferences.
  2. Click on "Exposé." "Dashboard & Exposé," or "Exposé & Spaces," depending on your version of OS X. Then click on the Exposé tab along the top of the panel.
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  3. In the Active Screen Corners section, set each drop-down menu to "---". This will prevent the mouse pointer from triggering Exposé when moved to the screen corners.
  4. In the Exposé section, you'll see a list of three Exposé actions, which can be assigned to the keyboard and/or mouse. Alongside each is two sets of drop-down menus. The lefthand set is for setting keyboard assignments, and the righthand set is for setting mouse button assignments. Set these to "---" to disable them.

Note: This is a per-user setting in OS X. It will need to be set for each user account on the computer.

Related:
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