On a button click we are saving a model and invoking a popup,sometimes its not displaying the popup

On a button click ,we are trying to save account model and then in the same button we are trying to invoke popup. So every time we click this button ,it will save the account details and then invoke the popup which will show the saved data.
Sometimes this popup is not displaying or comming

Sounds like you are occasionally having model save failures.  Currently the action framework does not automatically stop and warn the user if the save failed.  It just stops working.  

So we reccomend always putting a “failure condition action” underneath the model save action. 

Add a message that says “Save failed”  or somthing like that.