If the user clicks multiple times on a published  application it will launch several instances of the application even if "Limit to one instance per user" is set on the application.

Fixed in CWA 2402 CU2 

• When you click on an app, the spinner starts but stops immediately before the app opens. This allows you to click on the app multiple times, which might cause the app to fail to open. [CVADHELP-25951]

Problem Cause

User clicks on application too many times in succession in  short period