etsuko195 Said:
"I installed update is to my computer and now my screen is black and I only see searching circle, what can I do"
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Reinstall the macOS:
The update failed in one manor or another(likely from connection. Sometimes, changes are made to your Mac (i.e. Updates), and then settings (i.e. for ports), become manipulated, technically. So, reinstalling the macOS will place moved items back to where they should be, and will replace damaged system files. There are two steps: backup, then perform the reinstall. In depth: Go Here: How to reinstall macOS from macOS Recovery - Apple Support
Important:
Try using Ethernet, and then proceed with reinstalling the macOS. Through use of Ethernet, you would less likely lose the connection.