If the rendered device configuration for the VLAN description contains newline characters populated from the virtual network's description field, the commit operation fails because JUNOS and JUNOS-EVO devices do not support multi-line string for the VLAN description.

This is a known bug AOS-54198 (Commit failures in the JUNOS and EVO devices are caused by newline characters in the virtual network description field). Fix is currently targeting Apstra 6.1.0