Mac running slow and some applications don't open in standard mode, but in safe mode it works well

Question

I have an issue on my MacBook Pro (15-inch, mid 2010, macOS Sierra).

Some applications won't open, or don't work as expected, and generally I see the spinning pinwheel and macOS is really slow.

Also, often when I shut down I see a black screen, but not completely turned off, so I have to shut down by pressing the power button for 3-4 seconds.

Sometimes applications like Google Chrome or Final Cut Pro don't work well, often freezing up or not opening.

But all these issues disappear if I boot up in safe mode (applications work well, restarting and shutdown always work, no frozen apps, etc).

I tried to:

follow the guidelined to isolate the issue on this article: https://support.apple.com/en-us/HT201262 but I don't have any login items.
create a new user profile, but the issue isn't fixed.

My question is: What differences are there between safe mode and standard mode? What can I disable to isolate the issue?

Run Hardware Test. Hold D or option-D and turn on the mac. Let go once the test or "starting" symbol appears — John Keates, Jul 07 '17 at 01:06
I tried, but the Apple HW Test doesn't start and returns a " -3403D" error code — Giordano, Jul 14 '17 at 10:19
Sounds like a bad HDD/SSD to me. Try option-D or CMD-D for internet diagnostics. — John Keates, Jul 14 '17 at 14:39

Monomeeth · Accepted Answer · 2017-07-06T23:32:42.323

5

One place to start is testing your Startup/Login items, as it's likely to be something that's getting loaded during normal startup (e.g. a Startup/Login item, a font you've installed, etc) that's causing the problem.

So I would:

Startup normally
Go to System Preferences > Users & Groups
Select the Login Items tab
Take a note of your Login Items
Now remove all of them by highlighting them and clicking on the - button below
Restart your computer

Now your Mac will boot up without those login items loading. Test this and see if the problem persists.

If the problem does persist, I'd then remove any fonts you've installed yourself.
If the problem goes away you know one (or more) of the Login items were causing the problem. You can then go back and add them back one by one until you've identified the culprit.

Let me know how you go.

[EDIT]

I forgot to answer your question about what the difference is between booting into Safe Mode and booting normally. In a nutshell, booting into Safe Mode:

doesn't load Login Items and any custom fonts you've installed (which is what my answer above is based on)
ensures that only macOS kernel extensions are loaded
runs a number of additional checks during startup (e.g. verifying/repairing your drive's directory, etc)
deletes various caches

The last two can result in your system effectively repairing itself if your problems are related to corrupted caches or directory issues. In your case, since the problems didn't go away after previously booting into Safe Mode, the problem is most likely related to Login Items or 3rd party kernel extensions.

edited Jul 06 '17 at 23:32

answered Jul 06 '17 at 22:26

Monomeeth

64,558

Thanks for answering Monomeeth. I removed every login items (actually there was only Spotify), restarted my computer, but the issue persists. – Giordano Jul 14 '17 at 10:28
I've restored standard fonts and tested again. The issue is still there. – Giordano Jul 14 '17 at 10:36
How can I view/check the 3rd party kernel extensions installed on this machine? – Giordano Jul 14 '17 at 10:36
2

You can enter the following command into Terminal: kextstat | grep -v com.apple to list 3rd party kernel extensions. You may want to copy and paste the command so you get it exactly right. In case you don't know, Terminal is found within the Utilities folder, which itself is found within the Applications folder. – Monomeeth Jul 14 '17 at 10:37
2

After several trials, I found that uninstalling completely Flash Player from all the browsers fixed the slowness issue. – Giordano Nov 23 '17 at 10:25
Thanks for the update! :) That's something worth remembering and I'm sure will help others! – Monomeeth Nov 23 '17 at 10:33

score 3 · Answer 2 · answered Aug 05 '19 at 08:00

3

this solution might be weird but it worked for me. Turn off your Wi-Fi and try to open your applications again.

answered Aug 05 '19 at 08:00

Mostafa Shena

31

https://apple.stackexchange.com/questions/289070/mac-running-slow-and-some-applications-dont-open-in-standard-mode-but-in-safe#comment387769_289078 Here OP mentions that Flash player was an issue. – anki Aug 05 '19 at 10:35
I have no idea what it might be caused by, but I just started having the issue and this seems to fix the issue. Now, the question is, what exactly the case is. – mrpasqal Nov 12 '20 at 21:07
Well, I guess this was the actual reason behind my case: https://sneak.berlin/20201112/your-computer-isnt-yours/ – mrpasqal Nov 17 '20 at 20:38

score 0 · Answer 3 · answered Jun 22 '18 at 16:22

0

My problem was running icloud. Once it was disabled, the computer runs as expected.

answered Jun 22 '18 at 16:22

Tom Ciesielka

1

Mac running slow and some applications don't open in standard mode, but in safe mode it works well

3 Answers3

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