Hi, Winscp!
It's probably caused by low PC specifications.
For details, see the requirements of the VCN C/S client on the PC hardware.
The C/S client currently works with the Windows 7 operating system.
The PC hardware requirements for the client are as follows:
CPU: The performance is not lower than core i5.
Dominant frequency: The value must be greater than or equal to 3.2 GHz.
Memory: The value must be greater than or equal to 3 GB.
Hard disk: The value must be greater than or equal to 500 GB.
Graphics card: The performance is not lower than Radeon HD 6850 or GeForce GTX 550 Ti.
Network port: At least one 1000M network port.
Monitor: At least 22 inches.
Solution
Change the stream to secondary and lower the camera resolution.