NRE in today's build?

[Skyranch]

After updating our server, fails to start and the log has this stack trace:
NullReferenceException: Object reference not set to an instance of an object
  at Construction.AttributeSetup (UnityEngine.GameObject rootObj, System.String name, Boolean serverside, Boolean clientside, Boolean bundling) [0x00000] in <filename unknown>:0 
  at PrefabAttribute.PreProcess (IPrefabProcessor preProcess, UnityEngine.GameObject rootObj, System.String name, Boolean serverside, Boolean clientside, Boolean bundling) [0x00000] in <filename unknown>:0 
  at PrefabPreProcess.ProcessObject (System.String name, UnityEngine.GameObject go, Boolean isBundling, Boolean resetLocalTransform) [0x00000] in <filename unknown>:0 
  at PrefabPreProcess.Process (System.String name, UnityEngine.GameObject go) [0x00000] in <filename unknown>:0 
  at GameManager.FindPrefab (System.String strPrefab) [0x00000] in <filename unknown>:0 
  at GameManager.WarmupInternal () [0x00000] in <filename unknown>:0 
  at GameManager.Warmup () [0x00000] in <filename unknown>:0 
  at Bootstrap+<GameInit_Warmup>c__Iterator4.MoveNext () [0x00000] in <filename unknown>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in <filename unknown>:0