I received the following message “an error occurred while downloading 16.1.1”. What should I do?

Hi acumming,

Thanks for posting in Apple Support Communities! Restarting your device can resolve the issue with updating so if you haven't already, Restart your iPhone. If it continues after restarting, we suggest removing the update and downloading it again:

1. "Go to Settings > General > [Device name] Storage.
2. Find the update in the list of apps.
3. Tap the update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest update."

-If your iPhone or iPad won't update

This will download a fresh version. If you don't see the option to delete it or if you continue to run into error messages, we suggest updating through a computer.

Update your iPhone, iPad, or iPod touch with iTunes or Update your iPhone, iPad, or iPod touch with the Finder

Cheers!