I understand it's related to my map, but I don't understand how to fix it

[5.8s] Spawning World

[5.8s] Spawning World 

[2.7s] Terrain Mesh

[2.7s] Terrain Mesh 

[77.0s] Rail Meshes

[77.0s] Rail Meshes 

IndexOutOfRangeException: Index was outside the bounds of the array.

IndexOutOfRangeException: Index was outside the bounds of the array.

  at TrainTrackSpline.GetInitialVector (TrainTrackSpline track, TrainTrackSpline+TrackPosition p, TrainTrackSpline+TrackOrientation o) [0x00042] in :0 

  at TrainTrackSpline.AddTrackConnection (TrainTrackSpline track, TrainTrackSpline+TrackPosition p, TrainTrackSpline+TrackOrientation o) [0x000a3] in :0 

  at CollateTrainTracks.g__CompareNodes|5_2 (System.Boolean ourStart, System.Boolean theirStart, CollateTrainTracks+<>c__DisplayClass5_3& , CollateTrainTracks+<>c__DisplayClass5_4& , CollateTrainTracks+<>c__DisplayClass5_5& , CollateTrainTracks+<>c__DisplayClass5_6& ) [0x00084] in :0 

  at CollateTrainTracks.Process (System.UInt32 seed) [0x00297] in :0 

  at WorldSetup+d__15.MoveNext () [0x007a7] in :0 

Hello procedural map and no problem personnaly:

[54.6s] Spawning World
[2.0s] Terrain Mesh
[5.5s] Rail Meshes
[5.3s] Train Track Collation
[13.9s] Processing World​

map size +4000

Tanki

Hello procedural map and no problem personnaly:

[54.6s] Spawning World
[2.0s] Terrain Mesh
[5.5s] Rail Meshes
[5.3s] Train Track Collation
[13.9s] Processing World​

map size +4000

ask author maybe for helping you? 

idk why you've this error personnaly, can't help you more