Login Window ScreenShot Problem

Question

Login Window ScreenShot Problem

Using Mac OS X El Capitan 10.11.5 on a MacBook Pro (Retina, Mid 2012), I get an endlessly spinning beach ball if I do the following:

Sleep (in order to get the login screen)
Press [Ctrl]+[Cmd]+[4] a few times in a row, then
[Ctrl]+[Cmd]+[3] a few times in a row, then again
[Ctrl]+[Cmd]+[4] a few times in a row.

As far as I see, [Ctrl]+[Cmd]+[4] is supposed to take a partial screen shot of the login screen (LWScreenShot ....png in the Desktop folder). And that works, if I press that key combination just once. But it crashes if I do it multiple times. I guess this is not reentrant.

One of my co-workers could reproduce the problem on his computer (same model, same OS). It is not reproducible on an older version of Mac OS X.

To resolve the issue, I have to do a power cycle.

MacBook Pro with Retina display, OS X El Capitan (10.11.5)

Posted on Jun 24, 2016 6:28 AM

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Answer 1

dialabrain

Level 10

122,549 points

Jun 24, 2016 6:38 AM in response to ThomasMueller

First Command+Shift+3 takes a screenshot of the entire screen.

Command+Shift+Control+3 sends the screenshot to the clipboard.

same with Command+Shift+4.

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Answer 2

Jun 24, 2016 6:52 AM in response to dialabrain

Well, I know what the key combinations are _supposed_ to do. That's not the problem. The problem is the beach ball of death.

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Answer 3

dialabrain

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122,549 points

Jun 24, 2016 6:54 AM in response to ThomasMueller

The key combinations you posted were incorrect was my point.

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Answer 4

Jun 24, 2016 7:19 AM in response to dialabrain

The key combinations in the login window are not the same for Mac OS X El Capitan 10.11.5. The key combinations you posted are correct if already logged in. However, in the login window with that version of Mac OS X, in order to get a screenshot (saved to the Desktop directory), you have to press [Ctrl]+[Cmd]+[3], not [Shift]+[Cmd]+[3]. And to do a partial screen shot, use [4] instead of [3]. I don't think there is a way to send to clipboard (well I didn't try that).

As I wrote, with a different version of Mac OS X, the problem is not reproducible. And I think the key combinations are different.

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Answer 5

dialabrain

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Jun 24, 2016 7:23 AM in response to ThomasMueller

Let me put it this way, on my late 2015 27" Retina iMac, running OS X 10.11.5, the key combination is as I stated. Perhaps mine is the only one.

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Answer 6

dialabrain

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122,549 points

Jun 24, 2016 7:30 AM in response to dialabrain

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Answer 7

Jun 24, 2016 7:37 AM in response to dialabrain

Yes I have the same settings. However, those are just used if already logged in. (I assume each user could have a different shortcuts). Even if I disable or change those shortcuts, I can get a screen shot in the login window, using [Ctrl]+[Cmd]+[3]. I don't think there is any way to disable or change the shortcuts for the login window. I guess the keyboard shortcuts are hardwired in the login window.

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Answer 8

Jun 24, 2016 7:42 AM in response to ThomasMueller

I think what could have some influence is the keyboard layout. With keyboard layout "Unicode Hex Input", both [Ctrl]+[Cmd]+[3/4] as well as [Shift]+[Cmd]+[3/4] work. I ran into the problem with the "Swiss German" keyboard layout. My coworker (who also got the beach ball of death) uses the "US" layout.

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Answer 9

dialabrain

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Jun 24, 2016 7:57 AM in response to ThomasMueller

Do you both have non-US keyboards? Because on my US Keyboard, switching input source to "Unicode Hex Input" does not work with both.

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Answer 10

Jun 24, 2016 8:01 AM in response to dialabrain

I have a Swiss German keyboard, and can switch to "Unicode Hex Input". My coworker has a US keyboard and keyboard layout configured. Both of us didn't try to get a beach ball with the "Unicode Hex Input"; we got that with the regular layout.

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Answer 11

dialabrain

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122,549 points

Jun 24, 2016 8:06 AM in response to ThomasMueller

Well, I don't have a Swiss German keyboard to test. I also don't get a spinning beach ball when I take screens of the login window with either US or Unicode layouts and only Command+Shift+3/4 works for me…

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Answer 12

Jun 24, 2016 8:13 AM in response to dialabrain

Well, what you did is "Log Out". Not "Sleep". I can't reproduce the problem with "Log Out" either, and the keyboard shortcuts work there quite well. But not when I put it to "Sleep".

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Answer 13

dialabrain

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Jun 24, 2016 8:19 AM in response to ThomasMueller

Sleep (in order to get the login screen)

I have no idea what you are talking about now. Why would you want a screen shot of the screen sleeping? It would just be black.

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Answer 14

dialabrain

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Jun 24, 2016 8:35 AM in response to ThomasMueller

If you mean take a screen shot of the unlock screen, everything I posted still applies and I get no beach ball.

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Answer 15

Tom Gewecke

Level 10

115,946 points

Jun 24, 2016 9:47 AM in response to dialabrain

dialabrain wrote:

Well, I don't have a Swiss German keyboard to test.

But you can set your input source to Swiss German via system prefs/keyboard/input sources if you want to test that. I think bugs in the the shortcuts for different input sources are not so uncommon.

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