Random error messages in editor

[LukeStampfli]

Describe the bug
Got randomly spammed in editor with error messages about RpcQueue:

NullReferenceException: Object reference not set to an instance of an object
MLAPI.Messaging.RpcQueueProcessor.ProcessReceiveQueue (MLAPI.NetworkUpdateStage currentStage) (at Library/PackageCache/com.unity.multiplayer.mlapi@ddf9d9baf8/Runtime/Messaging/RpcQueue/RpcQueueProcessor.cs:38)
MLAPI.Messaging.RpcQueueContainer.ProcessAndFlushRpcQueue (MLAPI.Messaging.RpcQueueContainer+RpcQueueProcessingTypes queueType, MLAPI.NetworkUpdateStage currentUpdateStage) (at Library/PackageCache/com.unity.multiplayer.mlapi@ddf9d9baf8/Runtime/Messaging/RpcQueue/RpcQueueContainer.cs:114)
MLAPI.Messaging.RpcQueueContainer.NetworkUpdate (MLAPI.NetworkUpdateStage updateStage) (at Library/PackageCache/com.unity.multiplayer.mlapi@ddf9d9baf8/Runtime/Messaging/RpcQueue/RpcQueueContainer.cs:62)
MLAPI.NetworkUpdateLoop.RunNetworkUpdateStage (MLAPI.NetworkUpdateStage updateStage) (at Library/PackageCache/com.unity.multiplayer.mlapi@ddf9d9baf8/Runtime/Core/NetworkUpdateLoop.cs:149)
MLAPI.NetworkUpdateLoop+NetworkPostLateUpdate+<>c.b__0_0 () (at Library/PackageCache/com.unity.multiplayer.mlapi@ddf9d9baf8/Runtime/Core/NetworkUpdateLoop.cs:232)

To Reproduce
I don't know I was just dragging some cubes around to build a level and it happened.
Expected behavior
It should not happen

Screenshots

Environment (please complete the following information):

• MLAPI Version: release/0.1.0

[LukeStampfli]

Restarting the editor made it go away. Without restarting every scene change or nearly every action I did resulted in error messages appearing

[will-mearns]

Committed to fixing this as part of https://jira.unity3d.com/browse/MTT-529

[jeffreyrainy]

Fixed by #588