Q: ios 9.3.2 update not working

Get help with iOS update and restore errors - Apple Support

Check for communication issues

If you see error 1671, iTunes is downloading necessary software. Wait for the download to finish and try again. To see how long the download should take, you can click the down arrow in the upper-right corner of iTunes.

If you see one of the issues below, your computer might not be able to connect to Apple servers or your iPhone, iPad, or iPod touch:

• 17, 1638, 3014, 3194, 3000, 3002, 3004, 3013, 3014, 3015, 3194, 3200
• "There was a problem downloading the software."
• "The device isn't eligible for the requested build."

Check for communication issues between iTunes and Apple software-update servers. If you still see the error message, check for issues with third-party security software.