Hi Diego,
The error suggests that the device was shut down during the compression process.
We have released a possible solution in the 32 Beta firmware version. In this version, the compression should be finished correctly even if the device is shutting down simultaneously. This fix will also be included in the subsequent stable releases.
In your case, I’d suggest performing the survey again and checking the Logging tab to see if your logs are completely compressed and saved on your Reach after you stop logging.