After right-clicking on a reference file and selecting Settings, the window "Reference Attachment Setting for." opens, but the "header" and half of this window is not visible. It appears above the Microstation window.
Select focus in the Attachment Settings dialog box
go to your arrow keys and press one of them to begin the move dialog command.
Once you have the dialog moving with the arrow keys, use your mouse to place the dialog box in your required location.
Cannot move dialog box/window (header not visible)https://communities.bentley.com/products/microstation/w/microstation__wiki/15313/cannot-move-dialog-boxwindow-header-not-visible