Why I can't upgrade my galaxy note 2?

[AC Question]

It told me that my device had been modified.so have what method can let me upgrade my galaxy note 2 by normal?

 

[srkmagnus]

It told me that my device had been modified.so have what method can let me upgrade my galaxy note 2 by normal?

It seems that you may be rooted and/or installed a custom rom? If so, that explains the not being able to update error, which is common for rooted devices. You'll need to restore to a factory firmware then update. If you have the latest update to flash then use that rather than accepting the updated ota.