I have a matchmaking pool and it worked well with UE 4.16. A side creates a session and another finds and joins it.
I'm still able to create and join a session, but, since the update to UE 4.17, the server side crashes after some seconds the client has joined the session. It crashes only when using the Oculus subsystem and a matchmaking session (works well when using the Null subsystem and a normal session).
It crashes with this error
[2017.09.08-10.24.01:995][ 94]LogWindows: Error: === Critical error: ===
[2017.09.08-10.24.01:995][ 94]LogWindows: Error:
[2017.09.08-10.24.01:996][ 94]LogWindows: Error: Assertion failed: HasReceivedClientPacket() [File:D:\Build\++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Engine\Private\NetConnection.cpp] [Line: 684]
So the problem is the method HasReceivedClientPacket() in the NetConnection class.
This method has been introduced in UE 4.17 (it does not exist in 4.16) and this is what it does:
FORCEINLINE bool HasReceivedClientPacket()
return !!InternalAck || Driver->ServerConnection != nullptr || InReliable != InitInReliable;
May you investigate on this problem?