During a Multi-User Editing session with two or more team members two or more users can take control of the same actor and move it to different locations in the viewport at the same time.

However, if those users let go or release control of that object at about the same time ( within milliseconds ), that object can show up in two or more different locations within the scene ( viewport ).

Two users try to take control of the same actor. Steps:

  1. UserA begins moving/dragging a static mesh actor in the viewport.
  2. While UserA is moving/dragging, UserB grabs a hold of the same actor, and starts moving it in a different direction in their own viewport.
  3. If UserA and UserB stop moving/dragging the mesh at relatively the same time the mesh will show up in a different position to UserA than to UserB.   The multi-user session does does not update either client session.   

There are a few variations of that, but basically we have noticed potential for confusion when two users try to move the same actor at the same time.

Technically, the last user to have control of the mesh should win - but in this case there is no winner.

Network / latency lag may play a factor in this bug.  Adding distance between users may help reproduce the bug.   We were able to reproduce the bug by connecting from two different locations ( LA and Vancouver ).

Steps to Reproduce
  1. Start a multi-user session
  2. UserA begins moving/dragging a static mesh actor in the viewport.
  3. UserB selects the same static mesh and also moves it in their own respective viewport to a different location ( while UserA still is controlling it on their end ).
  1. Both UserA and UserB release the mesh at the same time ( within milliseconds ).   The mesh will appear at two different locations - at the last location each user moved/dragged it to - ( causing each user to seeing a different scene ).

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CreatedSep 12, 2023
UpdatedFeb 14, 2024