Arduino Uno Upload error: avrdude: verification error, first mismatch at b

Hello,

During the upload of a sketch I get the following error:

avrdude: verification error, first mismatch at byte 0x0042
         0x15 != 0x17
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch

This happens with all sketches except the example "Blink". Blink is currently running en seems to do fine. Any other sketch i try to upload fails.

This is the board information:

BN: Arduino/Genuino Uno
VID: 2341
PID: 0043
SN: 75335313537351412170

I use Arduino IDE 1.8.5 with the following settings:

board: arduino/genuino uno
programmer: AVRISP mkII

Anyone familier with this problem? Any possible solutions?

I am trying reburn the bootloader with an cheap USBASP from dealextreme but without success so far.