Security Settings for QuickLookUIService?

Question

Security Settings for QuickLookUIService?

I am often asked if I want to 'lower the security settings for "QuickLookUIService"' when select a .m4v file. How would I do that? Or how can I dismiss this dialog forever?

macOS High Sierra (10.13.5)

Posted on Jun 7, 2018 12:23 PM

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Answer 1

John Galt

Level 10

161,666 points

Jun 9, 2018 7:47 AM in response to kingfisher500

Some time ago Apple permitted the addition of "Audio Units"—third party plugins that can be used to preview audio files, for example. There is no way for me to know which of those products you may have installed on your Mac ("HandBrake" might; I wouldn't know) but I have never known them to be used for nefarious purposes. In light of that knowledge I suggest selecting "Lower Security Settings" so that the QuickLook UI will stop nagging you.

Refer to Finding Audio Units plug-ins on your computer - Apple Support.

If none of that makes any sense to you look for things like Perian (for instance).

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Answer 2

Jun 9, 2018 10:26 AM in response to John Galt

I found two files, one in each of those folders:

A52Codec.component, which has been there since 2011; and

Flip4Mac WMA Import.component, which has been there since 2013.

I don't know if they serve any purpose or not.

I think that I have discovered what is causing the issue and I think that I have fixed it. The default app for those .m4v files is show in "get info" as QuickTime. When I select the file in the finder, the next column shows a spinning time icon. I believe that the finder is attempting to show a QuickTime preview, but QuickTime is unable to open the file, so I get that alert and dialog, which does not actually do anything when I click it.

So, in "get info" I changed the default app for this type of file to the VLC app. Now, I get the spinning timer icon in the next column, but no alert. I can live with that. If there is an app that can preview .m4v files, I don't know what it is and would not really use it. Now, I can drag the video to iTunes without any annoying alert or I can double click and open the video in VLC.

Thanks for your help. I have been posting about this issue in various ways for a couple of years now and, of the few person to respond, you are the first to have any useful information.

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Answer 3

John Galt

Level 10

161,666 points

Jun 8, 2018 6:29 AM in response to kingfisher500

The reason that dialog appears is not obvious. Normally, merely selecting a file should not result in the appearance of any dialog box.

Please determine if the same problems occur in "Safe Mode": Use safe mode to isolate issues with your Mac - Apple Support.

Needless to say, if you are using any non-Apple "anti-virus", "cleaning", or "Internet security" junk, anything at all in that broad category of useless garbage, don't. A lot of things won't work if you do..

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Answer 4

John Galt

Level 10

161,666 points

Jun 9, 2018 9:00 AM in response to kingfisher500

Check the contents of all those folders (the Plug-Ins folders) and let me know what you find. I don't believe Apple includes anything any more, so whatever you find may be old, no longer supported, or no longer useful.

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Answer 5

Jun 11, 2018 6:13 PM in response to John Galt

This was more than just helpful. I trashed both of those files, and reset the default app for .m4v files to QuickTime. Now, when I select a file in that format, I still do not get a preview, but neither do I get an alert. When I double click the file, it opens in QuickTime and plays without any problem.

So, it seems that one of those Codec.components was causing both issues.🙂

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Answer 6

Jun 9, 2018 7:33 AM in response to John Galt

Thanks for your response. I have had this issue ever since I upgraded my OS to 10.13.

I followed your advice and restarted in "Safe Mode". This issue remained. I get this alert message whenever I select a file that I have encoded in .m4v format with Handbrake. All I want to do is drag the file to iTunes, which I can do, but the alert is annoying. I can dismiss it, but I would like it to never appear again.

Here, FYI, is a Screen Shot of the dialog box. If "Lower Security Settings" is an option, there surely must be someplace to do this and fix the issue, but I have not been able to find it. I may have something to do with QuickTime as that is the default app for this kind of file. QuickTime, however, does not actually open the file.

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Answer 7

Jun 9, 2018 8:29 AM in response to John Galt

Clicking on Lower Security Settings does not fix the problem. It brings up the message "operation could not be completed.

I will check and see what Finding Audio Units plug-ins on your computer - Apple Support has to offer.

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Answer 8

John Galt

Level 10

161,666 points

Jun 11, 2018 5:14 AM in response to kingfisher500

kingfisher500 wrote:

I found two files, one in each of those folders:

A52Codec.component, which has been there since 2011; and

Flip4Mac WMA Import.component, which has been there since 2013.

I don't know if they serve any purpose or not.

I checked several Macs, all of which are running High Sierra. Although several older ones contained the A52Codec, none of the newer ones do.

I know Flip4Mac is not required.

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Answer 9

Jun 11, 2018 6:14 PM in response to John Galt

Thanks. I have trashed both files. If I do need them, I can always re-install.

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