Resolve issues preventing installation of MacOS

I recently tried installing a fresh copy of MacOS Mojave on a student’s MacBook. After selecting the “Install MacOS” option, I received a message saying “This copy of the install MacOS Mojave application is damaged and can’t be used to install MacOS.” For some reason, this seems to be caused by an incompatible time showing in the system. There are similar error messages that seem to be resolvable by the same method. These messages include:

  • The installer payload failed signature check.
  • This copy of the install MacOS Mojave application can’t be verified. It may have been corrupted or tampered with during downloading.

To resolve the issue, restart, booting to your install flash drive, connect to WiFi, and run the Terminal app from the Utilities dropdown. In Terminal, enter the following:

ntpdate -u

Then try installing MacOS.

Using a VirtualBox Virtual Machine to Maintain iPad App Purchasing in iTunes – Post High Sierra

The recent High Sierra MacOS update brings us iTunes 12.7 which loses the ability to purchase apps for iPads associated with an Apple ID from within iTunes. There are convoluted methods of downgrading iTunes 12.7 to 12.6 to regain that capability, but it’s a pain to keep preventing Apple’s updates from forcing a user to lose this capability.

For most individual users, this isn’t much of an issue, but for institutional users, it makes it more complicated to acquire and distribute apps to iPads.

My solution is to build a VirtualBox machine with an original (un-updated) High Sierra MacOS with iTunes version 12.6. Whenever I need to access an Apple ID tied to a specific iPad account, I just fire up the MacOS VirtualBox, log into the associated iTunes account, acquire the needed app(s), and then log out. Since I have the iPads set up to auto-download apps purchased with the account, the apps typically show up on the device without additional intervention.

Let me know if you could benefit from a clone of my MacOS machine or need additional guidance on using VirtualBox.

Shady – for super granular control of your Macbook screen brightness

On a recent trans-Pacific flight, I was doing some work on my Macbook. All was fine with the in-flight WiFi working pretty well. But when they turned off the lights after dinner, my screen was painfully bright-even on it’s lowest setting.

You can use shift-option-F1/F2 to gain some fine-tuning control over your screen’s brightness, but if you need more, there’s Shady – a tiny li’l utility that basically writes a variably transparent grey layer over your screen. That’s all. It’s great. Get it.

Shady - screen shader

Changing Extensions in Finder – Disable Verification

When you change a file extension in Mac OS, you are asked to confirm that you actually want to do so. This can be annoying to those who routinely change say, .txt extensions to .csv. Thanks to KirkMC’s post in MacWorld, a simple Terminal command will disable that confirmation popup:

defaults write FXEnableExtensionChangeWarning -bool false

Then just relaunch Finder for the change to take effect:

killall Finder