Crash in TryLocalMatchmaking

[roncli]

Unhandled Exception detected: ArgumentNullException: Argument cannot be null.
Parameter name: key
 
(Filename: /home/builduser/buildslave/unity/build/artifacts/generated/common/runtime/DebugBindings.gen.cpp Line: 51)

System.Collections.Generic.Dictionary`2<string, System.Collections.Generic.List`1<NetworkMatch/LocalMatchmakingPlayerInfo>>.TryGetValue (string,System.Collections.Generic.List`1<NetworkMatch/LocalMatchmakingPlayerInfo>&) <0x001fe>
(wrapper dynamic-method) NetworkMatch/<TryLocalMatchmaking>c__AnonStoreyF.NetworkMatch+<TryLocalMatchmaking>c__AnonStoreyF.m__0_Patch0 (NetworkMatch/<TryLocalMatchmaking>c__AnonStoreyF,DistributedMatchUp/Match) <0x00253>
NetworkMatch.TryLocalMatchmaking (System.Collections.Generic.List`1<DistributedMatchUp/Match>,DistributedMatchUp/Match,System.Collections.Generic.Dictionary`2<string, System.Collections.Generic.List`1<System.Collections.Generic.KeyValuePair`2<string, int>>>) <0x001b8>
NetworkMatch.NetSystemDoLocalMatchmakerLogic (DistributedMatchUp/Match[],DistributedMatchUp/Match,System.Collections.Generic.Dictionary`2<string, System.Collections.Generic.List`1<System.Collections.Generic.KeyValuePair`2<string, int>>>&) <0x002d0>
(wrapper dynamic-method) LocalLANHost/<FindGameSessionToCreate>c__Iterator2.LocalLANHost+<FindGameSessionToCreate>c__Iterator2.MoveNext_Patch0 (LocalLANHost/<FindGameSessionToCreate>c__Iterator2) <0x0021d>
(wrapper dynamic-method) LocalLANHost/<DoBackfillRequest>c__Iterator4.LocalLANHost+<DoBackfillRequest>c__Iterator4.MoveNext_Patch0 (LocalLANHost/<DoBackfillRequest>c__Iterator4) <0x00ea7>
LocalLANHost.DoBackfillMatchTick () <0x00034>
LocalLANHost.DoTick () <0x00065>
NetworkMatch.NetSystemDoTick () <0x0021d>
NetworkMatch.Update () <0x00033>
Overload.NetworkManager.Update () <0x0003b>
(wrapper dynamic-method) Overload.GameManager.Overload.GameManager.Update_Patch2 (Overload.GameManager) <0x0059e>

The issue is a "PlayerId" is null somewhere. Line of code causing it is highlighted below.