Cannot unbind my HIK vision device

When I scanned my HIKvision DVR to connect, it says , 'this device already been addred by another account'.
I tried to unbind it. But it gives an error ' operation failed 9999' , while entering the admin passwd and captcha code.

I logged in to the hik-connect site and there is no device connected to that account.

I installed sapd in my computer , and it shows my device as online.I tried to unbind it from there also, but it also failed , showing a 'server internal error'.

I cleared all...

Cannot unbind my HIK vision device