How to Rename Multiple Files at Once on a Mac
The Finder has had a batch rename tool built in for years, and a lot of people still rename files one at a time because it is hidden behind a menu item that only appears…
Mac Charging Stops at 80%? That Is macOS Protecting the Battery
A Mac that sits at 80% and reports “not charging” looks like a fault, and it is almost always deliberate. Modern macOS holds the charge back to slow the battery’s chemical ageing — a battery…
Spotlight Not Working on a Mac: Check This Before Rebuilding the Index
When Spotlight stops finding things, the usual advice is to rebuild the index. That works often enough to keep getting repeated, and it is also the most expensive thing you can do — a full…
“No Space Left on Device” on a Mac: Where the Space Went
No space left on device is an honest error from the kernel: a write was refused because the filesystem had nowhere to put it. The disk is full. What makes it confusing on a Mac…
AirDrop Not Working on a Mac: Check the Interface It Runs On
AirDrop fails in a way that gives you nothing to work with: the other device simply is not there. No error, no explanation, just an empty sharing sheet. The reason it is so opaque is…
Mac Stuck on the Loading Screen: How to Narrow It Down
A Mac sitting on the Apple logo with a progress bar that has not moved for twenty minutes is the hardest kind of problem to troubleshoot, because the machine cannot tell you anything while it…
“zsh: permission denied” on macOS: The Three Causes and Their Fixes
zsh: permission denied looks like one error, and it is really three. The shell says it when a file has no execute bit, when the thing you pointed at cannot be executed at all, and…
“Disk Not Ejected Properly” on Mac: What Causes It and How to Eject Safely
The “Disk Not Ejected Properly” notification appears after the fact: a volume that macOS still had mounted is suddenly gone. Pulling a cable is the obvious way to cause it, but it also shows up…
Finder Not Responding on Mac: How to Relaunch It and Find the Cause
Finder stops redrawing, the spinning wheel appears, and clicking a window does nothing. Relaunching Finder is the standard first move, and it is safer than force quitting a regular app: Finder is managed by launchd,…
How to Check an App’s Code Signature on a Mac with codesign
When you download an app outside the App Store, codesign is the built-in way to check who actually signed it and whether the copy on disk has been tampered with. It reads the signature that…