DS-2CD852-MF-E won't update

[slovenija]

Hi guys, I am form Slovenia so sorry for mistakes.

I have 3 network cameras.(DS-2CD852-MF-E). They all have v2.0 build090316 and they all are WR. They work fine with iVMS..(I can see picture)
The problem is that I cant't update them. (I need onvif support for NVR)
I tried via internet explorer but can not login, becouse netvideoOCX does not work.
I tried via iVMS4200, but says upgrade filed.
I tried via tftp.. and gets this:
[2015-08-10 20:55:18] Device[192.0.0.64]test tftpserver
[2015-08-10 20:55:18] Connect client success [192.0.0.64]Success
[2015-08-10 20:55:18] Start file transmitting[C:\***\Auto Update\digicap.dav]
[2015-08-10 20:55:31] Completed file[C:\***\Auto Update\digicap.dav] transmit

firmware that I use: DS-2CD8xx,7xx,82xx,72xx,71xx IP Camera Firmware v5.1.0_131202
I even tried hard reset camera, but did not work..
What should I do? I have no idea...

thanks for your help!

 

[jordanb]

I'm pretty sure that tftp has to say something along the lines of "system update complete" if you leave it running after you have the completed file message does it come up with the update complete message?

 

[slovenija]

Nothing came up.. I leaved it for 1h and nothing..
can I try firmware from another camera?

EDIT:
Firmware Version: V2.0 build110426

I found this firmware on internet. I can update with iVMS and tftp... But why I can not update with newest 5.1.?