Upload succeeded but verify failed....

I recently purchased an APM2 and have been trying to upload the latest firmware to it. When I do, I get this error:

Upload succeeded but verify failed: exp C got 14 at 0

I've had the same problem using 3 different USB cables and on 2 different computers.  I've double checked that the USB baud rate is 115200.  I'm running Mission Planner 1.2.11mav 1.0 and trying to upload ArduCopter V2.7.3 Quad (I have the same problem loading any of the configurations).  I'm running on Windows 7 Home Premium.  The board has V2.4 silkscreened onto it.

I have a second APM2 which I can update without any problems using the same configuration.

Any idea how I can get this board updated properly?  Seems like a hardware problem to me.

I've posted this problem on the Mission Planner forum about a month ago and haven't had any responses so I thought I'd try here.  

I also sent e-mail to 3DR support twice (once a month ago and again yesterday) and haven't heard back.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • I had the same problem:

    "upload succeeded but verify failed: exp 8c got DC at 102254".

    As for me, the problem happened because I use Windows VM on MAC (VMware fusion hypervisor). It's very common issue when you use Serial port on a VM.

    Try to use Windows box to upload the firmware. It helped me so potentially it may help you.

  • Hi Bruce

    Got the same error as you on my new APM2.5.  

    Did try latest software og PM = no good (Upload succeeded, but verify failed: exp76 got 21 at 2)

    Did try in CLI mode.... got this " NNNNNNNNNNNNNfN:$H@VxxxmaB;89///5Q! @ *@`5@E

    "3 989000Z(@`st: %u
    bytes free: Error: pure virtual call ?naninfovf.H?G!A??
    ````````?i3O!331!"2122h111113A3t3312223 u8:]K{~+!!!!! C!E!"s!! _!!;!-!!!! ! 7! +!!! !"m!"G! +!!! !" !! ! ! ! ! !! !!/! ?! ! ! ! !!! !!!!h"!S!!"!" !h""w!! !
    !!!e!!!) %!#!!g!"c]E?$[O
    Piz*8LQ.iz@PhrF#aXil}i-=M\{L., 1BS 5401 %&EU&QO>?9e==?


    @>=o;>=o;L>u< @
    #=>@{.>@{.>@L>,@?? @?=d @?=dL>L>@ @ @ @,
    !{NTTg })'kk~?h



    Init ArduCopter V2.9.1b

    Free RAM: 2211
    FW Ver: 120

    load_all took 1040us
    (g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(g(  "

    Did also try Arduino with the special APM25 version = no good. Got this "

    avrdude: verification error, first mismatch at byte 0x0000
    0x45 != 0x0c
    avrdude: verification error; content mismatch " In every program uploaded code. Even small ones.

    And i have now read alot of docs, and the sad answer is that the board is conclusively doomed.

    I've only programmed it 8 times :(

    Many people have the same error, and i think it's the building of board's architecture in some way.

    I also have a Multiwii PRO and i have programmed it 100 times. And its still working.

    But now my APM2.5 goes in the bin and so does my project :.(   unless i get my fingers in one of these USB programmers.

    (in between the 8 times of programming, it flew perfectly with ALT HOLD aso)



  • I managed to get it working through changing com port settings in de device settings to XON/XOFF or Hardware. Also make sure you have 115200, n,8,1 there..

  • Developer

    when you load other firmware is it always the same error? ie "got 14 at 0"

    also what do you have plugged into the apm. try and unplug everything apart from the usb.

  • Developer

    Have you tried with arduino?

This reply was deleted.


Neville Rodrigues liked Neville Rodrigues's profile
Jun 30
Santiago Perez liked Santiago Perez's profile
Jun 21