Swarm Failed To Kick Off ,map and level stream

There are some maps named ‘Room’,‘Full’. Some static meshes are in these maps

Opening map ‘Full’ i drag the map ‘Room’ under it in levels panel

Then i set persistent level ( map ‘full’) invisible and the sub map ‘Room’ visible, there is a error message 'Swarm Failed To Kick Off - File In Use By Process’ when building the light

But if i open the map ‘Room’ to build, no error

HI ytianlong,

As I typically do, I ran a quick test to see if I could just reproduce the Swarm Failed to Kick Off issue using your description for the level setup, but everything checked out and built fine.

Use the suggestions on this page to go through and try to see if that resolves your issue.

Thank you!