Reset Printing System on Mac

If you're having printing issues with multiple printers (not just one or two), you may want to reset the printing system (Warning: this will remove your installed printers, and you'll have to install them again).

Go to System Preferences.

Select Printers & Scanners.

Right-click on a printer and then select Reset printing system....

Re-add the printers.

Get back the old Numbers default Print View

One of our users likes to see a print preview by default in Numbers. This was available in the older version of Numbers, but it's gone from the newer version of Numbers.

Unfortunately, the most viable solution for this is just to keep using the old version of Numbers.

If you're complaining about this issue, you likely already have the older version of Numbers. It will appear in the /Applications/iWork '09. If you don't have it, you also likely don't have this issue (because you're used to using only the new version of Numbers).

If you have an already-saved document that you want to open in Print View by default, go to File > Export To > Numbers '09

Just click Next.....

Name your exported document. Click Export.

Right-click on the exported file and select Get Info (for you keyboard shortcut–wedded folks, that's Cmd-I).

Find the Open with: section and then select (2.0).

Click Change All... and then click Continue.

Click View > Show Print View.

/System/Library/Keychains empty… and repercussions

The issue

We ran into a weird situation once, in which a user could not update anything. Trying to update Adobe Flash ended in an immediate error (Application Initialization Error), launching the Mac App Store led to the App Store saying it couldn't be contacted, and Chrome saying it was updated when it was several versions behind. Pretty much anything that had to contact a server for updates... couldn't.

The solution

After rebooting, checking for malware, failed proxy connections, and a bunch of other potential issues, we found out that the /System/Library/Keychains folder was empty.

So we copied the contents of that folder from another Mac, and then, magically, everything worked!

Very obscure issue and obscurer solution. Thanks to J. Pruden for finding it!

Exporting GarageBand to Google Drive on the iPad

When you try to share a GarageBand project out from the iPad, the immediately apparent options may include only Facebook, SoundCloud, and YouTube (yes, even if you select the More option).

If you want to export your project to Google Drive, you may have to take a few extra steps.

export garageband to google drive 01
Select your project by either tapping Select or long-pressing on the project icon itself.

export garageband to google drive 02
Once it's selected, click the share button (looks like an up arrow pointing out of a rectangle).

export garageband to google drive 03
Select Open in...

export garageband to google drive 04
Before you can select what to open the project in, you'll have to fill in some details about the song. Fill those in.

export garageband to google drive 05
Then you should see a lot more applications appear to share it in, including Open in Drive. You may have to do a bit of horizontal scrolling to get it to appear, depending on how many shareable-to apps you have installed.

export garageband to google drive 06
Once Google Drive opens, you'll then be prompted to upload the song. Select Upload.

Getting Started with Munki (not monkey)

5 April, 2018 update: This page used to have a tutorial that walked you through setting up a bunch of GUI tools to manage and keep up-to-date a Munki server. I've reconsidered, and I don't think that's the best approach for new Munki administrators to take to learning Munki.

First Steps

Here are a series of links you should read and follow, in this order, to explore Munki on your own:

  1. Demonstration Setup: Walks you through a very basic setup, using a Mac as a Munki server and another Mac (or even the server itself) as a test Munki client. Even though you can do so, I'd highly recommend against setting up a Mac running to be your Munki server. If you use a Mac, just use regular macOS with the built-in Apache.
  2. Overview: If you're absolutely new to Munki, you should really understand the basic mechanics of it and what catalogs and manifests are. If you read the overview and are still confused, ask for clarification from other Munki administrators (see links in Getting Help).
  3. How Munki Decides What Needs To Be Installed: This is one of the most frequently asked questions from new Munki administrators, so it's very important you understand why you may have a Munki item that's in an endless install loop (and how to fix it).
  4. An opinionated guide to Munki manifests : Some opinions on how you should structure your manifests in Munki.
  5. Another opinionated guide to Munki manifests: Some more (related) opinions on how you should structure your manifests in Munki.

Getting Help

And here are some great places to go for help, if you have Munki-related questions:

  1. MacAdmins Slack #munki channel
  2. Munki-Discuss Google Group
  3. MacEnterprise mailing list

Server Setup

Want to secure your Munki repo and/or move it to Linux? You may find these links handy:

  1. Using https / self-signed certificates and basic authentication with Munki: If you want to stay with macOS and have basic authentication on an internal-only server.
  2. Certbot Apache on macOS: If you're going for basic authentication on a public-facing server, and you want a proper (not self-signed) SSL certificate.
  3. Setup a Munki repo on Ubuntu 14.04 - Part 1: Yes, I know it says 14.04, but the basic instructions still work for 16.04, and they'll probably work for 18.04, too.
  4. Certbot Nginx on Ubuntu 16.04 (xenial): Proper SSL certificate for Ubuntu (again, if your server is public-facing).
  5. Using Munki With SSL Client Certificates: Basic authentication not enough security for you? Set up revokable client certificates instead.

Munki-related Helper Tools

Need other helper tools?

  1. AutoPkg: Allows you to automate downloading and installing new software into your Munki repo. Get to know the command-line tool well first if you choose to also install the (no longer maintained) GUI management for it called AutoPkgr.
  2. MunkiAdmin: A great graphical frontend for managing your Munki repo (after you've already understood how the pieces work together... and, frankly, even with MunkiAdmin, I'd still recommend using munkiimport on the command-line to manually import new items that don't come through AutoPkg). As an alternative, you may want to check out mwa2, which is web-based.
  3. MunkiReport-PHP or sal: If you want to add in a reporting piece to see what your Munki clients are up to.

Create an auto-logoff script for Windows 7

One Use Case

I'm not really sure how useful this is to other folks, but we're in a primarily Mac environment and have a Windows computer joined to Active Directory that's handy to use for people's password changes.

Once people have changed their passwords... no need to be logged in any more, so this just logs people out shortly after they've changed their passwords.

You may, of course, find other uses for this, and you can adapt the script as necessary.

Create the script

Using Windows' Notepad (or another downloaded text editor like Notepad++), create a new document and paste this code in:

:: Don't display commands
@echo off

:: Display message to user
echo You will be logged out at the end of the countdown.
echo Close this window if you want to stay logged in.

:: Wait 10 seconds
timeout /t 10

:: Log out
shutdown /l

Save the file as autologout.bat on your desktop or someone else you can easily reference later.

Test the script

Now find the autologout.bat file you saved and double-click it. It should have a countdown and then log you out.

Move the script to the startup folder for every user

If the script worked, go to C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup

Then, copy or move your autologout.bat file to that new location.

It should now log people out 10 seconds after they log in.

Enable AirDrop on wired connections

AirDrop for wireless only by default


By default, Apple enables AirDrop only for wireless and not for wired connections. So if you'd like to enable AirDrop for wired connections, launch up the (which you can find in Applications > Utilities), and then paste in one of the following two commands.

Command for only the logged-in user

defaults write BrowseAllInterfaces 1

Command for all users

sudo defaults write /Library/Preferences/ BrowseAllInterfaces 1

Refresh AirDrop

You may have some luck relaunching Finder, but I'd recommend rebooting your computer entirely, particularly if you're changing the setting for all users, and not just the logged-in one.

Cloning an image using Thunderbolt and Disk Utility

Why would you do this?

  • It's fast. Over Thunderbolt, cloning a roughly 30 GB (of used space) image takes only a few minutes.
  • Minimal additional cost. Sure, you probably paid money for your Macs, but this method uses only included software... and one US$40 cable.
  • No external media or extra setup. You don't have to network your computer, install additional software, or have an external hard drive. You can go straight from computer to computer with just a Thunderbolt cable.


  • Two Macs—one source, one target.
  • Rename the hard drive on the source Mac to something unique (don't call it Macintosh HD, which is the default). Easiest way to do this is to go to Finder > Preferences and then check or tick Hard Disks under Show these items on the desktop. Then, when you see the hard drive icon appear on your desktop, you can rename it.
  • A Thunderbolt cable.
  • The main hard drive partition of the source Mac must be equal to or lesser in size than the target Mac hard drive. For example, if you are imaging from 250 GB to 250 GB, that's okay; if you're imaging from 250 GB to 500 GB, that's also okay; but if you're imaging from 1 TB to 500 GB, that won't work.


Note: If you're using El Capitan (10.11) or later, the procedure has changed. More details at Cloning an image using Thunderbolt and Disk Utility (post–El Capitan)

The procedure below is for Yosemite (10.10) and earlier.

  1. lightningboltOn the target Mac, reboot the computer while holding down the T key on the keyboard to boot it into Target Disk mode. If you have done so successfully, you will see what appears to be a white lightning bolt on the screen.
  2. On the source Mac, reboot the computer while holding down the Cmd and R keys on the keyboard to boot into Recovery Mode.
  3. Then, connect the Thunderbolt cable to both Macs.
  4. On the source Mac, select Disk Utility from the available options.
  5. diskutility
    Once Disk Utility launches up, click on the main partition (the one you renamed earlier) of the source Mac. Since Disk Utility can sometimes load up the target Mac visibly higher or lower than the source Mac, it's critical that you have them uniquely named (that's why we renamed the drive earlier). So click on that unique name.
  6. Click Restore. You should see the source as the uniquely-named drive.
  7. Then drag the main partition of the target Mac over to the Destination area.
  8. Click Restore.
  9. That's it! Once it's done, you can boot your target Mac into regular mode, and it should be a clone of your source Mac.

Acer Monitor and Mac Computer

We had a bit of trouble at first getting some Acer K272HUL monitors to work with some Macs on campus, and Google searches came up with threads like this, which offered some helpful tips, but not a full solution.

So if you happen to have an Acer K272HUL (or perhaps a similar model) and some Mac desktops, you may find this post helpful.

Problem: We couldn’t get the Acer monitors to recognize our Mac computers (running Yosemite, though I’m not sure that made a difference) using HDMI cables. Then we tried using a MiniDisplayPort-to-DVI cable, and the Acer monitor recognized the connection but wouldn’t display at full resolution (we could get tiny resolution in the center of the screen or pixelated stretched resolution).

Solution: First, on the monitor, go to the settings and make sure the DP version is set to 1.1 and not 1.2.

Then get a MiniDisplayPort-to-DisplayPort connector.

That’s it. Full resolution.

Update (9 January, 2018): So the above blog post was for Mac Pros connecting to the monitor. If you try to connect a MacBook Air running High Sierra, the HDMI connection will “work” but may flicker. You should still use a Displayport connection.