Most likely VFB window is on another non-existed monitor.
You may try to follow two approaches to bring it back to the main monitor.
1.From the taskbar click with right mouse button over V-Ray Frame buffer preview icon, select Move, then press one of the Arrow keys on the keyboard and move the mouse to the main monitor - if everything is OK VFB should be pinned to the mouse cursor.
2.Press render button, then hold Windows keyboard button and press a few times each of the Arrow keys on the keyboard. Please note that you should complete this operation during the rendering, if render ends the window-focus will be moved to another window.
Let us know if the above tips helped or not.
The VFB is actually a real pain in the ass. Clicking on the VFB button doesn’t do anything if the window is already open (minimized), moving it to the foreground or actually activating it would be helpful but I need to go to the taskbar everytime and activate it there, not really intuitive. Can this behaviour be changed? I remember a time this was different.
Yes, for the V-Ray Next beta we’ll move VFB entirely to QT-library, hopefully it will work much better than now.
