EX3300 can't disable xe-2/3 for VC.

Hello.

I need to use all four 10Gb port as network ports.

so I'd disabled xe2/3 as VC ports but link is still down

root@ex3300# run show virtual-chassis

Virtual Chassis ID: 492c.d68c.639c
Virtual Chassis Mode: Enabled
                                                Mstr           Mixed Route Neighbor List
Member ID  Status   Serial No    Model          prio  Role      Mode  Mode ID  Interface
0 (FPC 0)  Prsnt    GD021xxx446061 ex3300-24t     128   Master*     NA  VC

Member ID for next new member: 1 (FPC 1)

root@ex3300# run show interfaces xe-0/1/3
Physical interface: xe-0/1/3, Enabled, Physical link is Down
  Interface index: 156, SNMP ifIndex: 565
  Description: 
  Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Speed: 10Gbps, Duplex: Full-Duplex, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Enabled, Media type: Copper
  Device flags   : Present Running Down
  Interface flags: Hardware-Down SNMP-Traps Internal: 0x4000
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 3c:61:04:ef:18:de, Hardware address: 3c:61:04:ef:18:de
  Last flapped   : 2017-02-23 13:21:40 MSK (01:10:39 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : LINK
  Active defects : LINK
  Interface transmit statistics: Disabled

  Logical interface xe-0/1/3.0 (Index 97) (SNMP ifIndex 566)
    Flags: Device-Down SNMP-Traps 0x40004000 Encapsulation: ENET2
    Input packets : 4
    Output packets: 10
    Protocol eth-switch
      Flags: Trunk-Mode

root@ex3300# run show version
fpc0:
--------------------------------------------------------------------------
Hostname: ex3300
Model: ex3300-24t
Junos: 15.1R5.5
JUNOS EX  Software Suite [15.1R5.5]
JUNOS FIPS mode utilities [15.1R5.5]
JUNOS Online Documentation [15.1R5.5]
JUNOS EX 3300 Software Suite [15.1R5.5]
JUNOS Web Management Platform Package [15.1R5.5]

need any advice how to fix it.

thanks!