Upgraded my NVR's firmware, now computer screen blank?

[Vauxfan]

Yeah. Ds-7608ni-i2 with 2 cameras currently. I did have 2 x 4mp ds 2cd2347g2 models that worked faultless. Now I removed a 4mp till I mount it else where and put in the 8mp into another port on the nvr. Now it won't show the full image in HD mode on the 8mp or play back the alarmed notifications. The line detect won't set the nvr buzzer but does now pick it up and alarm.

The playback function is hit and miss. It's slow to load when it does. Plays in HD but other times it stalls at 88%
It stopped showing any thing the other day and when I went to test playback on the nvr because the app didn't work. The nvr would play either. Same type of error message. A reboot gave me playback via the nvr

 

[Vauxfan]

Just an update. Was playing around in nvr via Web link and tried a couple of things.
Configuration/ video&audio.
I changed the substream video quality from medium to low to lowest and it made no difference to the HD view via hikconnect. Screen had green screen as before and slow playback loading.

I did the same in main stream and I could change to HD at low setting. No green screen. playback was improved speed loading wise. Problem is.why would my hikconnect be using mainstream to view on and not substreem like its supposed too?
isn't mainstream what the nvr records in and substream what it should be sending to my phone app?
doesn't changing mainstream make the image quality low for the nvr recording. Surely this would make the image closer to 4mp than 8 meaning why have an 8 at all?
I take it this setting will make the image lower on the nvr as well In live mode?



Scratch that. Back to green screen this morning and notifications not loading on the 8mp

 

[Vauxfan]

After an nvr reboot it's done it again via playback in hikconnect. With in a week its done it again!!

That means the playback via the nvr will also not play.
Why is this happening?

What connections am I supposed to be stopping?