panic: sync: WaitGroup is reused before previous Wait has returned

[UnknownOre]

panic: sync: WaitGroup is reused before previous Wait has returned

goroutine 1 [running]:
sync.(*WaitGroup).Wait(0xc000072f00?)
C:/Program Files/Go/src/sync/waitgroup.go:141 +0x85
github.com/df-mc/dragonfly/server/world.(*World).close(0xc000214e00)
C:/Users/k/go/pkg/mod/github.com/df-mc/dragonfly@v0.9.7/server/world/world.go:1024 +0x85
sync.(*Once).doSlow(0xc001260000?, 0xc12143bf34086ce8?)
C:/Program Files/Go/src/sync/once.go:74 +0xc2
sync.(*Once).Do(...)
C:/Program Files/Go/src/sync/once.go:65
github.com/df-mc/dragonfly/server/world.(*World).Close(0x934060?)
C:/Users/k/go/pkg/mod/github.com/df-mc/dragonfly@v0.9.7/server/world/world.go:1013 +0x4a
stcraftnet.com/m/player.NewPlayer(0xc0012380f0, 0xc0007b6480)
C:/Users/k/Desktop/work/Proxy/player/player.go:16 +0x65
main.main()

code

w := world.New()
w.Close()