Window issue in extjs when reopening the window

Hi ,

I am getting the error: "Uncaught TypeError: Cannot read property 'addCls' of null" for the following Scenario

I have created two desktop Icons with Its Window called Masters and Projects. By clicking Masters Icon It opens the master's window , after closing the master window It works fine when reopening it , But In case of projects window It opens the window for first time only, then I close the project's window, again I am trying to open It. It does not work until page refresh or reload.

I have used close action: 'hide' and close action: 'destroy'. But I am getting the same error.

Ext.override(Ext.Window, {

closeAction: 'hide'

})

Please help me to do this Thanks in Advance.

Window issue in extjs when reopening the window