This article explains the procedure to fix if you are unable to do a preview during the NAT publish /update operation.

1. Delete and rediscover should fix the issue. However, if it is not possible to delete the device, then you can try the following steps.

2. Log in to the MySQL database using the command below 

mysql -ujboss -p$(grep mysql.jboss /etc/sysconfig/JunosSpace/pwd | awk -F= '{print $2}') build_db -A

3. Check whether the routing instance table is showing NULL

mysql>  select * from RoutingInstance;
+----+----------+---------+-------+------------+--------------+--------------------+---------------+---------------+--------------------+-----------------+-----------------+--------------+---------+
| id | domainId | version | name  | deviceName | instanceType | routeDistinguisher | vlanTagsInner | vlanTagsOuter | vrfTargetCommunity | vrfTargetExport | vrfTargetImport | hostingMe_id | vpls_id |
+----+----------+---------+-------+------------+--------------+--------------------+---------------+---------------+--------------------+-----------------+-----------------+--------------+---------+
| 65 |     NULL |       0 | vr-test | 1          |         NULL | NULL               | NULL          | NULL          | NULL               | NULL            | NULL            |            1 |    NULL |
+----+----------+---------+-------+------------+--------------+--------------------+---------------+---------------+--------------------+-----------------+-----------------+--------------+---------+
1 row in set (0.00 sec)

4. If the Routing Instance type field is showing a NULL value, validate the SRX configuration using below command

[email protected]> show configuration | display set | match instance-type
set routing-instances vr-test instance-type virtual-router

5. If the instance type is virtual-router, then update the value to 3 in the Instance type field table. Post which issue should be fixed

mysql> update RoutingInstance set instanceType=3 where id=65;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

6. If the issue persists, please contact JTAC support for further assistance.