Fixing DecoderException and Packet Size Errors with Connectivity Mod

A DecoderException or a "payload too large" error usually means a packet arrived that the receiving side could not parse. The Connectivity Mod is built specifically to catch these before they crash your session.

Identify the offending packet

When the error occurs, check your logs. The mod logs packets that are too large and shows their source, so you can see which mod or which action triggered the oversized payload. Note the packet name and the direction (client-to-server or server-to-client).

Use packet logging for detail

Enable the mod's packet logging feature before reproducing the error. Reproduce the crash or disconnect, then read the log. The logged packet contents will show whether the payload is malformed (wrong structure) or simply too big. Malformed packets usually come from a mod version mismatch; oversized packets usually come from a mod sending too much data at once.

Resolve it

For malformed packets, make sure client and server run matching mod versions. For oversized packets, the mod's connection fixes can help by handling the packet more gracefully, but the real fix is on the sending side. If you are the server admin, the mod's malformed-traffic protection will reject bad packets instead of letting them take down the connection.