Privacy, controlled by TCC and the Privacy & Security settings, can go wrong. Without documentation or good tools, it can prove hard to fix.
troubleshooting
How to use Ulbow to find just the log entries you need, using filters and predicates. Bring order to chaos.
The only place you’re likely to find that crucial piece of information about outgoing connections, bugs or problems is the log. How to get started.
Excessive CPU use by mds_stores is a common cause of sluggish performance. Explains what it does and what you can do bring it under control.
Why you should keep a copy of the Panic Log. How to check that your Mac isn’t the cause. And above all, don’t panic.
You might be lucky and solve it by inspiration. When that fails, fall back on a careful, thorough and systematic approach as explained here.
Requirements, which apps support it, how to access it in each of those, why some images don’t work, and how to troubleshoot it.
Signs of an SSD going down may be confusing, but when random apps seem to freeze, be suspicious. Diagnosis and recovery are also covered.
Should you be scared of ‘bricking’ your Mac? Just what does it mean, and what could you do about it? Don’t panic: it’s not a dragon to be slayed.
Apps may crash, but kernels panic. Don’t accept your Mac just panics often. It should never panic at all, and more than one panic a year needs to be properly investigated and reported.
The Eclectic Light Company 