In order to disable two-sided printing by default in all Mac OS applications (see this post to set double-sided printing per job), you need to edit your printer defaults using CUPS. CUPS is open-source software Mac OS uses to handle system printer settings.   First, enable the CUPS web interface. Open Terminal and type the following...

Are you having issues installing system updates for macOS? Some users report receiving an error message on their Mac when they go to Settings -> Software Update and attempt to install the latest system updates.   Unable to verify software update. You can try again to complete the installation.   The error message is vague and...

When you click a link from a website using Google Chrome, is it opening it twice in new tabs? The link opens exactly the same in both tabs. Resetting Google Chrome to defaults and clearing browsing history (cache, cookies, etc.) does not fix the issue. There seems to be a little bug that causes this to...

If you are unable to export photos from Mail into the Photos app on Mac (Mail app right-click -> Export to Photos) try the following fixes in order.   Ensure add to photos share menu is enabled. Go to System Preferences -> Extensions -> Share Menu -> Add to Photos is checked.   Verify your primary Photos...

When you attempt to launch a Citrix application, you immediately receive a message that prevents you from launching it.   You have not chose to trust “” the issuer of the server’s security certificate. Contact your help desk for assistance. You will need to manually install the root and or Intermediate Certificate Authority (CA) that the...

After updating iTunes, you may receive a message prompt in iTunes about a certificate that is invalid. The message may appear when you initially launch iTunes.   iTunes can’t verify the identity of the server “xp.apple.com” The certificate for this server is invalid.   Other domain names that may appear in the message include:   init.itunes.apple.com...