Summit Stacking "show stacking" shows slot role as none

Slot- FAILED (1) Card Mismatch

• Summit stack switches
• EXOS

show stacking 
Stack Topology is a Daisy-Chain
This node is not in an Active Topology
Node MAC Address   Slot Stack State  Role  Flags
----------------   ---- ----------- -----  -----
<MAC Address>      -    Active      Master ---
<MAC Address>      -    Active      None

show slot

Slots   Type     Configured State      Ports
--------------------------------------------
Slot-1 X460-24t  X460-24p   Mismatch
Slot-2 X440-48t  X440-48t   Operational

* - Indicates this node
Flags: (C) Candidate for this active topology, (A) Active Node
(O) node may be in Other active topology

1.  Type "unconfigure slot <slot number>"

   This slot will be rebooted as part of this operation.
   
    This will remove all port and vlan information for ports in this slot().
    Any ports on this slot that are members of load share groups will be removed
    from the load share group.
    Continue ? (y/N)

2. Please note that once the first step is done you want to reconfigure the ports of the unconfigured slot. 
3. Type "configure slot <slot number> module <module or node for which slot should be configured>"  (this is an optional step)