My iPhone 12 mini won't scan QR codes

Hi josef2016

Welcome to the Apple Community.

We are all Apple users, like yourself, doing what we can to help each other troubleshoot.

Wondering if your are opening the camera app,

and

selecting the rear facing camera, before you scan the QR code.

Also

if it is the one QR code, or many / all QR codes, that produce "No usable data.

and

whether your iPhone has the newest iOS 15.2 installed, or an earlier version.

All the best :-)

If it's not something that can be directly used by a built in app (like a vaccination QR code in Health) then it supposed to give you an option to look it up in Safari.

Thank you for your reply, Joe,

and for letting us know how you solved the situation.

Grateful to know you no longer have the difficulty.

Cheers :-)