Hi,
Please provide the output of 'show module cx detail'. Is you management ip is in the subnet of inside 'trusted' interface. if yes, then check if the management interface and inside interface both are in the same vlan on switch.
Also check if the management interface is 'UP'. If you are accessing it from outside, then check the management ip is natted correctly.
Hope it helps.
Regards,
Akshay Rastogi