Unable To Establish communication with configuration server

[chamBaso]

Dear Sir, 

            After changing controller static IP Address, I found system fully rebooted with the following and also when click Access Points in the gui, it shows operation has not completed and Empty Reply Message in the dialog box. Code Version in the controller is 7.0.8.0  

 copy running-config startup-config         
Building configuration. Please wait ...                             
/etc/init.d/meru-functions: line 17: ulimit: core file size: cannot 
modify limit: Invalid argument                                      
The system is not fully operational                                 
Unable to establish communication with configuration server         

One or more commands have failed.                                   
Use "show log running-config" to view the script log for more detail
s.                                   

       Thanks in advance if there is a solution. 

Thank You
Yours faithfully,
Chami