What I meant as Approved visa is my Dubai evisa which got approved or issued.
This needs to be attached as one of the document to your wife and sons application for visa to be issued.

Now we don't get on arrival visa you have use the online site if you need to visit dubai
Or use travel agents,
Try reloading the documents if you still find the message as "application in process" for more than 5 days or "document required....." message