avrdude: verification error, first mismatch at byte 0x0000 0x0c != 0x62

Hello,

Im very much confused with my UNO R3, i uploaded a code some quite few months back in my UNO, where it was working fine.

Now without having altered any of my circuits, i am trying to upload my code with some changes,im getting this strange error

"avrdude: verification error, first mismatch at byte 0x0000
0x0c != 0x62"

I tried some research to be able to solve the issue, but im running with kind of fuse bit being changed or clock speed altered, but im pretty sure i did not play around with these items.

Any help from you people, please . .

Thanks

taz