To add to Jitendra's question, at which step are you seeing this error ? is it at the beginning or middle of the workflow on a particular step ?Give as much as info you can so that we can try to solve the same.

Hi Krithi,You mean to say, no users are listed when you clicked on a dropdown arrow or when you type the user you want to impersonate ?If not tried, then try typing the user you want to impersonate and see if that gets listed !

As @Scott mentioned, use the button 'on' click event in JQuery, Refer [1] for the hint[1] https://docs.adobe.com/docs/en/cq/5-6-1/touch-ui/granite-UI-cheatsheet.html

If you have created cq:dialog, try double clicking on the parsys where you have included your component. It should open the dialog.

With this service, it seems to work only for UsersYou may have to write your own scheduler to send it for the groups if need be (You can refer to com.day.cq.dam.core.impl.MissingMetadataNotificationJob and write your custom service)

Think, the package has not been ported fully to your friend. If you are sending to him over an email, there might be a chances of jar file getting blocked.Did you try installing the package manager by yourself and see if you also encounter the same issue.

Hi Praveen,It looks like the aspect ratio of the image you have shown in the screenshot is not correct. If you upload the right image with the correct aspect ratio, it would work.

Also, check if the port is enabled to access

Essentially, it should update the same nodes !! If not there is some issue with your component behavior !Also, in any case there is no way AEM list all the unused nodes, it has to be handled manually or by customized services 

As @Scott mentioned, please give a specific usecase you are looking at. It depends on what you call it as stale nodes. Is it unused version nodes or unused content nodes. Each type of stale nodes should be handled in a different way. However, there is no such OOB feature to list all the stale/unused...