# Troubleshooting
import { Callout } from 'nextra/components'

<Callout type="warning">
  There will be a breaking SDK upgrade in the coming months. This upgrade will make the SDK a lot easier to build with.

This upgrade will affect the interface of the SDK dramatically, and will be coupled with a protocol change - stay tuned for information on early access to the new protocol testnet.

It will also be coupled with the documentation of the SDK on [crates.io](https://crates.io/).
</Callout>
## Lots of `duplicate fragment received` messages
You might see a lot of `WARN` level logs about duplicate fragments in your logs, depending on the log level you're using. This occurs when a packet is retransmitted somewhere in the Mixnet, but then the original makes it to the destination client as well. This is not something to do with your client logic, but instead the state of the Mixnet.
