If you work in a multi-screen environment especially if you have a laptop and you connect to multiple 2nd screens – meaning you connect to a 2nd monitor at work, at home and at various training center or customers – the probability of a floating dialogue boxes going missing if you are back on a single monitor is very high.
Obviously how this has come about is if you open a application say like AutoCAD on a 2 screen environment. You start up a task on AutoCAD that is maximised on screen 1. A related dialogue box might pop up asking you to input certain info related to the task. You can however move this dialogue box onto screen number 2 and complete the command. Usually windows will remember the position of the floating dialogue box and if you do the same task again opening the same dialogue box it should be on the previous position you moved it to. This works nice as the dialogue boxes are consistently in the same place.
The problem sometimes creep in when unplug the 2nd monitor and when you open AutoCAD and initiate the same command and dialogue box as before. Instead of the dialogue box being showed in the only monitor it thinks it should display the dialogue box in the non-existent 2nd monitor.
A workaround it to simply plug in the 2nd monitor temporarily and move the dialogue box back to the 1st monitor but sometimes this not possible as the monitor might be close to you.
The solution is to move the dialogue box to the center of you screen by using some keyboard strokes. If you realise that a dialogue box is missing then please do the following :
Press the ALT key and Spacebar together. This opens up the dialogue box options.
Press the M for Move.
Press any of the Arrow keys once on the keyboard. This makes the dialogue box stick to your mouse curser.
Now move your mouse to the center of your screen and left click the mouse.