Many users forget that scheduled tasks—like continuous recording, motion detection playback, or remote backup software—also consume playback channels. If a maintenance script is downloading footage from 4 cameras in the background, you may only have a few channels left for manual review.
If the system is showing stale playback sessions that won't disconnect (a known bug in older Hikvision units), a reboot will clear all active sessions. : Using iVMS-4200 on a PC and Hik-Connect
: Using iVMS-4200 on a PC and Hik-Connect on a phone at the same time for the same device can trigger this restriction. Recommended Solutions motion detection playback
If you are using Hikvision on a PC, the limit might be your computer's decoding ability or the network bandwidth. You can lower the stream quality to view more cameras. : Using iVMS-4200 on a PC and Hik-Connect