When using virtual desktop software like VirtuaWin, desktop switching can cause dialogs of memoQ to close without warning. Fortunately, there is a workaround for recent versions of VirtuaWin.
This will cause VirtuaWin to handle memoQ dialogs differently, avoiding the problem of abruptly closed dialogs. It is not yet known whether similar fixes are possible for other virtual desktop managers like Microsoft Virtual Desktop Manager.