When you double-click a file and expect to see it opened by the app of your choice, but instead it’s opened by the wrong app, or the wrong version of the right app, or maybe macOS refuses to open it at all. How to fix that.
troubleshooting
Have your Time Machine backups become irregular, or stopped altogether? Are software updates infrequent, or malware scans rare? Find the answers here.
Is there a memory leak in that app? How to tell, and what you can do about it. Also notes about rare leaks in kernel zone memory, which can cause kernel panics.
How to investigate an app that crashes when starting up, using log entries. Includes detailed instructions for one of the simplest adventures in the log, and a summary of code signature errors.
When an app can only run for a moment, it might seem hard to work out why it crashes. Here are useful clues from the crash log and elsewhere to help you get the app running properly.
How to discover what went wrong when a document doesn’t show the right thumbnail, but a generic icon instead. How to dive deeper to solve problems with 3rd party thumbnail and preview generators.
Use the mdimport and mdls commands to dump full information about all the metadata attributes found for a file, and those indexed by Spotlight.
Can be a Mac-saver if you have problems when your backup storage isn’t available. You don’t need to run Time Machine to make them, and can roll back in Recovery, as shown here.
My friend took it to extremes, travelling everywhere with a 30-foot rope in his suitcase. But he was right: would you be able to get to the fire escape? How that applies to problems with the structure of the internal SSD of an Apple silicon Mac.
It now consists of many discrete services. How to test CloudKit’s shared databases, iCloud Drive’s cloud storage, and whether your Mac can install from iCloud.
The Eclectic Light Company 