I get an exception in my save now, possibly because I removed the MES Wreckages mod:

Exception occurred: System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Enumerator.MoveNext()
at ModularEncountersSystems.Helpers.FactionHelper.GetFactionOwner(IMyFaction faction)
at ModularEncountersSystems.Helpers.FactionHelper.GetFactionMemberIdFromTag(String tag)
at ModularEncountersSystems.Spawning.PrefabSpawner.SpawnPrefab(SpawnGroupCollection spawnCollection, PathDetails path, EnvironmentEvaluation environment)
at ModularEncountersSystems.Spawning.PrefabSpawner.ProcessSpawning(SpawnGroupCollection spawnCollection, PathDetails path, EnvironmentEvaluation environment)
at ModularEncountersSystems.Spawning.SpawnRequest.CalculateSpawn(Vector3D coords, String source, SpawningType type, Boolean forceSpawn, Boolean adminSpawn, List`1 eligibleNames, String factionOverride, MatrixD spawnMatrix, Vector3D customVelocity)
at ModularEncountersSystems.Spawning.WatchedPlayer.ProcessPlayerTimers()
at ModularEncountersSystems.Spawning.PlayerSpawnWatcher.CheckPlayers()
at System.Action.Invoke()
at ModularEncountersSystems.Tasks.TaskProcessor.Process()
at Sandbox.Game.World.MySession.UpdateComponents()
at Sandbox.Game.World.MySession.Update(MyTimeSpan updateTime)
at Sandbox.MySandboxGame.Update()
at Sandbox.Engine.Platform.Game.UpdateInternal()
at Sandbox.Engine.Platform.Game.RunSingleFrame()
at Sandbox.Engine.Platform.FixedLoop.<>c__DisplayClass11_0.<Run>b__0()
at Sandbox.Engine.Platform.GenericLoop.Run(VoidAction tickCallback)
at Sandbox.Engine.Platform.Game.RunLoop()
at Sandbox.MySandboxGame.Run(Boolean customRenderLoop, Action disposeSplashScreen)
at SpaceEngineers.MyProgram.Main(String[] args)