Device Message explains the error codes, warnings and pop-ups on phones, computers, appliances and cars: what each one means, how urgent it is, and how to fix it safely.
A solid tire pressure light means a tire is at least 25% below its recommended pressure; one that flashes for about a minute then stays on means the monitoring system has a fault. What to do for each, cold-weather triggers, and when to stop.
A steady check engine light means get it checked soon; a flashing one means a misfire that can damage the engine and exhaust, so slow down and stop. What each means, the fuel-cap check, reading the code, and when to call a tow.
Gatekeeper couldn't confirm the app comes from an identified developer and was checked by Apple. How to decide whether to open it, the supported Open Anyway route on macOS Sequoia, and when to delete it.
A browser pop-up saying your computer is infected and telling you to call a number is a tech support scam. How to spot it, close it, and what to do if you already called or paid.
A core Windows process stopped, so Windows shut down to protect your files. What causes it, how urgent it is, and the fixes to try whether or not your PC still starts.
Your iPhone or iPad can't confirm the cable or accessory you plugged in works properly. The usual causes, how urgent it is, and fixes from a firm replug to cleaning lint out of the port.
Too many wrong passcodes lock your iPhone. What the message means, when waiting is enough, how the 72-hour previous passcode option works, and how to erase and restore safely.
Your iPhone found moisture in its charging port and stopped cable charging to protect the pins. How urgent it is, how to dry the port the way Apple recommends, and what not to try.
