Can't connect Nexus 4 to adb: unauthorized

Question

I have a Nexus 4 with Android 4.3 and I am trying to connect the device to a computer with Windows 7 64bit.

I installed the latest drivers and the latest adb

Answer 1

Сhange USB connection mode from MTP to Camera (for Nexus 7) or, possibly, to Mass Storage or something else (for other devices). This option is usually under Settings -> Storage. Then connect the device again, you'll get the authorization dialog.

MTP has been known to interfere with USB debugging -- these two did not work together at all on majority of older devices. Nexus 7 and many newer devices do allow both to work alongside, but this particular issue suggests it's not all that smooth yet.

Bonus -- checklist for when adb is not behaving well:

• adb kill-server followed by adb start-server
• (on device) Settings -> Developer Options -> USB Debugging -- switch off and on
• [Windows] Make sure you have the proper driver (your best bet is Universal Adb Driver by Koushik Dutta -- will handle any device)
• [Windows] Try turning off all fancy on-the-fly anti-malware scanners/firewalls
• [Linux] Make sure you have the proper UDEV rule in /etc/udev/rules.d/51-android.rules (again, universal solution: https://github.com/snowdream/51-android)
• [Linux] Make sure everything under ~/.android is owned by you, not root (and upvote this answer)
• restart device (yes, surprisingly, this is a valid measure, too)
• (Obviously) replug cable, try different cable, different port, remove any extender cables