Backup Job Fails on Older CPUs

Product version: 11.1

Last modified: 17 March 2026

Problem

Backup and backup copy jobs that use the Onboard Transporter on Windows fail shortly after starting, with the error:

Connection to the <Onboard transporter> transporter has been lost.

The issue occurs immediately after the job starts, before any significant data is transferred.

Background

On systems running older CPUs that do not support SSE4.2, the bh.exe process used by the Onboard Transporter crashes during backup processing when using FAST compression (Snappy + SSE4.2). As a result, the Transporter service becomes unavailable, and the backup job fails with a connection error.

This issue may affect any job type that relies on the Onboard Transporter, including backup and backup copy jobs.

Solution

Upgrade to NAKIVO Backup & Replication 11.2 or later to avoid SSE4.2 incompatibility and resolve the issue. If upgrading is not immediately possible, use one of the following workarounds:

Change the backup repository compression level from FAST to MEDIUM or BEST. These compression modes do not use the SSE4.2 and avoid the crash.

Run the backup job using a separate (non-onboard) Transporter on Windows instead of the Onboard Transporter.

Note

Replacing snappy.dll with a custom build compiled for older instruction sets may resolve the issue, but this approach is not officially supported.