CI_Controller $this->upload->data() !

Watching your video I see what's going on, but I couldn't tell you why without digging into your code a little more. I think you're just going to have to step through the code a line at a time and make sure everything's right. var_dump works, of course, but if you have a way to debug with XDebug that'd be even better. It's likely a small typo between field names, or something similar.

aright thank you sir , i noted up my code is working fine if i select one file and second file it will get empty , so
what im going to do , make form for each file better than mulitpart actually !
and there is not problem or error and im sure no bugs in my code but i have one thing and maybe it's the problem
the code what i wrote for update one file only , well i have no Reference for update 2 files in one moment .
thank you again.