Mac Error Messages Explained
Don’t worry — every mac user sees error messages from time to time. Here are 13 common ones, explained in plain English with step-by-step fixes.
High Priority — Fix These First
Your Computer Restarted Because of a Problem
Your Mac had a serious error and restarted itself. This is the Mac equivalent of a "blue screen." Your files should be safe.
Wi-Fi: No Hardware Installed
Your Mac cannot detect its own Wi-Fi hardware. This usually requires a restart or, in rare cases, a repair.
Medium Priority
Your Startup Disk Is Almost Full
Your Mac's main storage drive is running out of space. You need to delete some files to keep your Mac running smoothly.
Safari Can't Establish a Secure Connection
Safari is warning you that it cannot safely connect to the website. The website's security may have an issue.
Your System Has Run Out of Application Memory
Your Mac does not have enough working memory to run all the apps you have open. You need to close some apps.
Bluetooth Not Available
Your Mac's Bluetooth is not working. You will not be able to use Bluetooth devices like wireless keyboards, mice, or headphones.
Low Priority — Not Urgent
Application Not Responding (Spinning Rainbow Wheel)
An application on your Mac has frozen. The spinning colourful wheel (sometimes called the "spinning beach ball of death") means your Mac is struggling.
"App" Is Damaged and Can't Be Opened
macOS thinks the app you are trying to open may be unsafe or corrupted. This is a security feature called Gatekeeper.
Time Machine — Backup Failed
Your Mac could not complete its automatic backup. Your previous backups are still safe — the new one just did not finish.
External Drive Not Showing Up in Finder
You plugged in an external hard drive or USB drive but it is not appearing on your Mac. The drive might not be compatible or may need to be mounted.
This App Requires macOS [Version] or Later
The app you are trying to use needs a newer version of macOS than what you currently have. You may need to update your Mac.
AirDrop — No People Found on Mac
Your Mac cannot find nearby Apple devices to share files with. Both devices need to have AirDrop enabled and be close together.
Printer Is Offline
Your Mac thinks the printer is not available. The printer may be off, disconnected, or having a communication issue.
Can’t find your error?
Try searching for it on the main error lookup page, or browse errors for a different device.
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