What region of the world are you in? UK, Europe, somewhere else? Can you confirm what version of iVMS-4200 you are using?
Not sure if the same issue but I have been having quite a few issues with iVMS recently on Windows 11:
1) Often camera views get a time delay of up to several minutes. A close of the main view and re-start of the main view gets the cameras back to a current live view again. But for a security system that relies on a live view to be of any use this is a serious problem.
2) Often clicking on a camera view to switch to full-screen main stream it can take 30-seconds or more to get the main stream to show properly. If I close the main view and re-start the main view it seems to solve the issue for a while. Seemingly no pattern or regularity to this issue. Again, a serious problem for a security system.
3) Under normal running my iVMS (with 49 camera views) uses 1GB of memory and about 15-20% of CPU. But often now when I start it, it instantly uses many many GB of memory and 100% of CPU. Sometimes it almost kills the PC and I can barely even start task manager to kill it. A kill and re-start (or two) and I can usually get it back to running normally.
All issues only started happening at various times during 2023 and all persist to this day. I have updated to more recent versions lots of times (and un-installed/re-installed) but still have these issues regularly. Currently on v3.10.1.5 from the UK HikVision site.