SMD UNO fail to load avrdude: stk500_disable(): protocol error, expect=0x14, res

Using Arduino IDE 1.x
3

Spent a day with same error (Uno, Vista 32). Here's what fixed it for me:

  1. Uninstalled Arduino from device manager & deleted driver. (with Arduino unplugged)
  2. Connect Arduino to USB (should see green LED on & yellow bootloader "L" on)
  3. Select driver location **** do no not check box that says search sub folders*****

The little check box is key. The previous 50 attempts with the subfolder box checked installed the FTDI USB drivers which according to the FAQ are not compatible with the Atmega8U2 drivers:
"The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega8U2 programmed as a USB-to-serial converter."
After that step all is good again :slight_smile: