Bedrock Dedicated Server 1.26.31.1 – Malformed RakNet PONG Responses After World Upgrade
Summary
After upgrading to Bedrock Dedicated Server (BDS) version 1.26.31.1, existing worlds migrated from a previous server version become inaccessible to clients.
The issue appears to be related to malformed RakNet responses generated by the server during connection establishment.
Environment
Server: Bedrock Dedicated Server 1.26.31.1
Host OS:
Windows
Client: Bedrock Edition client 1.26.31.1
Network analysis tool: Wireshark
Description
When an existing world created on a previous BDS version is loaded in BDS 1.26.31.1, clients are unable to connect.
Packet captures show malformed RakNet PONG packets being sent by the server.
Observed behavior:
The client sends an unconnected PING.
The server responds with an unconnected PONG.
The returned PONG packet appears malformed in Wireshark.
Connection establishment does not proceed successfully.
Additionally, malformed RakNet PONG packets can be observed after the world is loaded and the server is running.
Expected Behavior
Server should return a valid RakNet unconnected PONG response.
Clients should be able to complete the RakNet handshake and connect successfully to the server.
Existing worlds should remain accessible after upgrading the server version.
Gergely Sinko
Bedrock Dedicated Server 1.26.31.1 – Malformed RakNet PONG Responses After World Upgrade
Summary
After upgrading to Bedrock Dedicated Server (BDS) version 1.26.31.1, existing worlds migrated from a previous server version become inaccessible to clients.
The issue appears to be related to malformed RakNet responses generated by the server during connection establishment.
Environment
Server: Bedrock Dedicated Server 1.26.31.1
Host OS:
Windows
Client: Bedrock Edition client 1.26.31.1
Network analysis tool: Wireshark
Description
When an existing world created on a previous BDS version is loaded in BDS 1.26.31.1, clients are unable to connect.
Packet captures show malformed RakNet PONG packets being sent by the server.
Observed behavior:
The client sends an unconnected PING.
The server responds with an unconnected PONG.
The returned PONG packet appears malformed in Wireshark.
Connection establishment does not proceed successfully.
Additionally, malformed RakNet PONG packets can be observed after the world is loaded and the server is running.
Expected Behavior
Server should return a valid RakNet unconnected PONG response.
Clients should be able to complete the RakNet handshake and connect successfully to the server.
Existing worlds should remain accessible after upgrading the server version.
Actual Behavior
RakNet unconnected PONG responses appear malformed.
Clients cannot establish a connection to the server when an upgraded existing world is loaded.
Comparison / Control Test
Using the same BDS 1.26.31.1 server installation:
Let the server to create a vanilla/new world allows clients to connect normally.
Server responds correctly and remains fully accessible.
The issue only occurs when loading an already existing world migrated from a previous version.
Migration Details
Only the following items were copied from the previous server installation:
World folder
server.propertiesNo plugins, extensions, custom server modifications, or additional components were installed.
Additional Notes
The problem appears tied to loading an existing upgraded world
A fresh/vanilla world on the same server version does not exhibit the issue.