This article provides a workaround for correcting the error condition.

Attempting to define and save a LAN network results in a transformation error.

Mist UI displays the following message:

Transformation Failed
Problems:
1: Error: / does not match the form /nn
2: Please send WAN Edge logs to Mist and contact customer support for further assistance.

The following errors appear in 128T-mist-agent logs:

ERR transform executor failed: exit status 1
ERR Configuration pipeline failed for version <ID>: transformation request failed.
ERR Apply Config Pipeline Errors:
ERR | LAN interface port_config[bond-0/0/1] references network AV that does not exist
ERR | LAN interface port_config[bond-1/0/1] references network AV that does not exist

A required site variable referenced in the LAN network configuration was missing.

Example configuration:

{{av_vlan}}             → 50
Network Name: AV
{{av_network_high}}.1/{{av_mask}}

The variable av_mask was not defined in the site configuration. As a result, Mist could not render a valid network prefix, causing the transformation to fail and the config update to be rejected.

Define the missing variable av_mask in the site configuration.

Steps

1. Navigate to the site’s WAN Edge configuration variables.
2. Add the missing variable:
   • av_mask → <appropriate subnet mask> (e.g., 24 or 30, depending on design)
3. Save the configuration.
4. Reattempt the LAN network update.

After adding the missing variable, the config update should go through.

If you face any further issues, please contact JUNIPER JTAC Support for assistance.