How to fix watchOS 'Unable to Install Update' error
Are you having problems installing a watchOS update on your Apple Watch? Getting an “Unable to Install Update” error, or perhaps a message that the update cannot be verified? Going around in a loop and not getting anywhere except increasingly frustrated?
Take a deep breath, because I have a fix that might just be what you are looking for.
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Here are the steps:
#1: Fire up the Watch app.
#2: In the Watch app — not iOS — click on General > Usage > Software Update.
#3: Click Delete.
#4: Click Delete again to confirm the removal of the watchOS software update.
#5: From the Watch app, click on General > Software Update to redownload the update.
That should be the end of your problems!