Unable to upgrade firmware

Hi there,

I am trying to upgrade the firmware on my ds-2cd2532f-i cameras through my K4 NVR and keep getting an error message saying "D1 - Upgrade Failed" on all the cameras.

I am using the latest V4 firmware on my K4 and the cameras are working fine.

I have another K4 and the firmware updates are working fine.

I have also used the batch update program and gives me an unknown error message.

Any ideas?

Cheers,
Epipen