user45449: I use an Arduino UNO with IDE 1.8.5 and for the last few days it doesn't let me upload any code. When I try, it pops up with the following error:
avrdude: verification error, first mismatch at byte 0x0042
         0x65 != 0x8d
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch

I really don't know what happened it used to work perfectly well. I even tried to upload blank code with nothing wired on and still the same error appears. I also tried with another USB cable, another PC, an older Arduino IDE but still nothing happens.
Any ideas ??
After checking so verbose output during compilation& upload it shows this:
Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Uno"
C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -hardware C:\Users\kat_t\AppData\Local\Arduino15\packages -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -tools C:\Users\kat_t\AppData\Local\Arduino15\packages -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\kat_t\Documents\Arduino\libraries -fqbn=arduino:avr:uno -vid-pid=0X2341_0X0043 -ide-version=10805 -build-path C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827 -warnings=none -build-cache C:\Users\kat_t\AppData\Local\Temp\arduino_cache_621253 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.1.1 -prefs=runtime.tools.avrdude.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9 -prefs=runtime.tools.avr-gcc.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2 -verbose C:\Users\kat_t\AppData\Local\Temp\untitled1895278478.tmp\sketch_may18b\sketch_may18b.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -hardware C:\Users\kat_t\AppData\Local\Arduino15\packages -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -tools C:\Users\kat_t\AppData\Local\Arduino15\packages -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\kat_t\Documents\Arduino\libraries -fqbn=arduino:avr:uno -vid-pid=0X2341_0X0043 -ide-version=10805 -build-path C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827 -warnings=none -build-cache C:\Users\kat_t\AppData\Local\Temp\arduino_cache_621253 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.1.1 -prefs=runtime.tools.avrdude.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9 -prefs=runtime.tools.avr-gcc.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2 -verbose C:\Users\kat_t\AppData\Local\Temp\untitled1895278478.tmp\sketch_may18b\sketch_may18b.ino
Using board 'uno' from platform in folder: C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21
Using core 'arduino' from platform in folder: C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21
Detecting libraries used...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "nul"
Generating function prototypes...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\preproc\ctags_target_for_gcc_minus_e.cpp"
"C:\Program Files (x86)\Arduino\tools-builder\ctags\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\preproc\ctags_target_for_gcc_minus_e.cpp"
Compiling sketch...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core
Linking everything together...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-gcc" -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p  -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp.o" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/..\arduino_cache_621253\core\core_arduino_avr_uno_7e7efc521bfa236d1e5438b10f2a9ebf.a" "-LC:\Users\kat_t\AppData\Local\Temp\arduino_build_834827" -lm
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0  "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.eep"
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-objcopy" -O ihex -R .eeprom  "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex"
Sketch uses 444 bytes (1%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/bin/avrdude -CC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/etc/avrdude.conf -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:i 

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/etc/avrdude.conf"

         Using Port                    : COM4
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
         AVR Part                      : ATmega328P
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    20     4    0 no       1024    4      0  3600  3600 0xff 0xff
           flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff
           lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : Arduino
         Description     : Arduino
         Hardware Version: 3
         Firmware Version: 4.4
         Vtarget         : 0.3 V
         Varef           : 0.3 V
         Oscillator      : 28.800 kHz
         SCK period      : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: reading input file "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex"
avrdude: writing flash (444 bytes):

Writing | ################################################## | 100% 0.06s

avrdude: 444 bytes of flash written
avrdude: verifying flash memory against C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:
avrdude: load data flash data from input file C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:
avrdude: input file C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex contains 444 bytes
avrdude: reading on-chip flash data:

An error occurred while uploading the sketch
Reading | ################################################## | 100% 0.06s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0002
         0x6b != 0x34
avrdude: verification error; content mismatch

avrdude done.  Thank you.


user46742: I feel there is an issue with the bootloader that you are using with your Arduino, or maybe there is a fuse bit error.
Do you have a programmer with you, such as the usbtiny or the usbasp. IF you have another Arduino which works, than you can use it as a programmer as well.
Read up about it here
https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard
Connect the programmer to the Arduino Board, and your computer.
Go to tools, select the Arduino board. Then tools>programmers>select the programmer you are using.Then tools>burn bootloader.
This will fix any fuse bit issues, while also uploading a fresh version of the Bootloader which works with your Arduino IDE.
I hope this helps.

45449: <p>I use an Arduino UNO with IDE 1.8.5 and for the last few days it doesn't let me upload any code. When I try, it pops up with the following error:</p>

<pre><code>avrdude: verification error, first mismatch at byte 0x0042
         0x65 != 0x8d
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch
</code></pre>

<p>I really don't know what happened it used to work perfectly well. I even tried to upload blank code with nothing wired on and still the same error appears. I also tried with another USB cable, another PC, an older Arduino IDE but still nothing happens.<br>
Any ideas ??</p>

<p>After checking so verbose output during compilation&amp; upload it shows this:</p>

<p>Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Uno"</p>

<pre><code>C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -hardware C:\Users\kat_t\AppData\Local\Arduino15\packages -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -tools C:\Users\kat_t\AppData\Local\Arduino15\packages -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\kat_t\Documents\Arduino\libraries -fqbn=arduino:avr:uno -vid-pid=0X2341_0X0043 -ide-version=10805 -build-path C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827 -warnings=none -build-cache C:\Users\kat_t\AppData\Local\Temp\arduino_cache_621253 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.1.1 -prefs=runtime.tools.avrdude.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9 -prefs=runtime.tools.avr-gcc.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2 -verbose C:\Users\kat_t\AppData\Local\Temp\untitled1895278478.tmp\sketch_may18b\sketch_may18b.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -hardware C:\Users\kat_t\AppData\Local\Arduino15\packages -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -tools C:\Users\kat_t\AppData\Local\Arduino15\packages -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\kat_t\Documents\Arduino\libraries -fqbn=arduino:avr:uno -vid-pid=0X2341_0X0043 -ide-version=10805 -build-path C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827 -warnings=none -build-cache C:\Users\kat_t\AppData\Local\Temp\arduino_cache_621253 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.1.1 -prefs=runtime.tools.avrdude.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9 -prefs=runtime.tools.avr-gcc.path=C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2 -verbose C:\Users\kat_t\AppData\Local\Temp\untitled1895278478.tmp\sketch_may18b\sketch_may18b.ino
Using board 'uno' from platform in folder: C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21
Using core 'arduino' from platform in folder: C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21
Detecting libraries used...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "nul"
Generating function prototypes...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics  -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\preproc\ctags_target_for_gcc_minus_e.cpp"
"C:\Program Files (x86)\Arduino\tools-builder\ctags\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\preproc\ctags_target_for_gcc_minus_e.cpp"
Compiling sketch...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR   "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\cores\arduino" "-IC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.21\variants\standard" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp" -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core
Linking everything together...
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-gcc" -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p  -o "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827\sketch\sketch_may18b.ino.cpp.o" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/..\arduino_cache_621253\core\core_arduino_avr_uno_7e7efc521bfa236d1e5438b10f2a9ebf.a" "-LC:\Users\kat_t\AppData\Local\Temp\arduino_build_834827" -lm
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0  "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.eep"
"C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\4.9.2-atmel3.5.4-arduino2/bin/avr-objcopy" -O ihex -R .eeprom  "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.elf" "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex"
Sketch uses 444 bytes (1%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/bin/avrdude -CC:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/etc/avrdude.conf -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:i 

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "C:\Users\kat_t\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino9/etc/avrdude.conf"

         Using Port                    : COM4
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
         AVR Part                      : ATmega328P
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    20     4    0 no       1024    4      0  3600  3600 0xff 0xff
           flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff
           lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : Arduino
         Description     : Arduino
         Hardware Version: 3
         Firmware Version: 4.4
         Vtarget         : 0.3 V
         Varef           : 0.3 V
         Oscillator      : 28.800 kHz
         SCK period      : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: reading input file "C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex"
avrdude: writing flash (444 bytes):

Writing | ################################################## | 100% 0.06s

avrdude: 444 bytes of flash written
avrdude: verifying flash memory against C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:
avrdude: load data flash data from input file C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex:
avrdude: input file C:\Users\kat_t\AppData\Local\Temp\arduino_build_834827/sketch_may18b.ino.hex contains 444 bytes
avrdude: reading on-chip flash data:

An error occurred while uploading the sketch
Reading | ################################################## | 100% 0.06s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0002
         0x6b != 0x34
avrdude: verification error; content mismatch

avrdude done.  Thank you.
</code></pre>
 46742: <p>I feel there is an issue with the bootloader that you are using with your Arduino, or maybe there is a fuse bit error.</p>

<p>Do you have a programmer with you, such as the usbtiny or the usbasp. IF you have another Arduino which works, than you can use it as a programmer as well.
Read up about it here<br>
<a href="https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard" rel="nofollow noreferrer">https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard</a></p>

<p>Connect the programmer to the Arduino Board, and your computer.</p>

<p>Go to tools, select the Arduino board.<br> Then tools>programmers>select the programmer you are using.<br>Then tools>burn bootloader.</p>

<p>This will fix any fuse bit issues, while also uploading a fresh version of the Bootloader which works with your Arduino IDE.</p>

<p>I hope this helps.</p>
