The Padlock icon in the bottom right hand corner of vMix can be used to lock certain buttons in vMix so they are not clicked accidentally.
When the icon is grey and open, everything is unlocked, when the icon is orange and closed, the functions below are locked:

  • vMix Close Button
  • Input Close Button
  • Open Preset
  • Last Preset
  • Recording Stop
  • Streaming Stop
  • External Output Stop
  • MultiCorder Stop