HELP! Lightroom Crashes Only with Adjustment Brush and only when using HDMI output!

Question

This is very frustrating. I use my Acer N56V laptop to teach Lightroom workshops. I use a 32 inch television as a display. When I have my laptop attached with an HDMI cable and try to use Lightroom's adjustment brush, it crashes. Either the screen and computer just shuts down or I get the Blue Screen of Death. I can do anything else! I can edit in Photoshop, do anything else in Lightroom or even Silver EFX Pro. I can even click on the adjustment brush. But the minute the brush hits the photo (and not before), the computer crashes. If I don't have it attached to the HDMI or if I use a Serial cable, no issues. It's only the adjustment brush and only the HDMI output.
I called Adobe and they said it was because my onboard video card was primary and not the Nvidia. I called Acer and they said it's auto detect. I also tried making the Nvidia card primary and it still happened. Any ideas???

Answer 1

You have switched the overlay mask to always show. Fortunately, it's easy fixed i.e. tap the O key. Shift+O will cycle the overlay through various colours
Other Adjustment Brush and Graduate Filter shortcuts and modifiers are listed them below:
Open Adjustment Brush - K
Open Gradient Tool - M
Show/hide Pin - H
Always Show - Shift + Cmd/Ctrl+H
Show Selected/Never Show - Shift+H
To increase Amount - Right Arrow
To decrease Amount - Left Arrow
To increase/decrease brush size -  ] / [
To increase/decrease feather - Shift+] / Shift+[
Set Flow Amount - Number Keys
To commit  and/or start new a brush stroke or gradient - Enter / Return
To delete the selected pin - Delete
Holding down - Alt/Option key activates erase mode
Toggle Auto Mask On/Off - A
Pressing O toggles on/off the overlay
Shift+O cylces through alternative colours for overlay
To constrain gradient to vertical/horizontal  - hold down Shift plus drag
To invert the gradient - '
To scale from center - Alt/Option plus drag