DirectCam hosts running JustCamIt on Windows 10, in conjunction with AVG Anti-virus may encounter application crashes when someone enters their room in Group or Private mode, (i.e. when you would normally be prompted to accept a new visitor).
There is a known conflict with AVG and some applications running on Windows 10. JustCamIt appears to be one of them.
Solution
Use an alternative, compatible, anti-virus program such as Avast, which protects Windows 10 PCs for free.
Temporary Workaround
Whilst evaluating which alternative anti-virus program to install, you can use JustCamIt Lite, although this is an emergency solution and will not allow clients on mobile devices to access your chat room.