I think the ngOnDestroy method in dialog.js wants to unsubscribe listeners which doesn't exist.
Also mentioned in this forum entry:
Thanks i think the issue is what you mentioned i will review that and get back to you from here.
@Mrtcndkn nice, thanks for the fast reply :)
@Mrtcndkn Any updates on this?
@Mrtcndkn This same issue exists in confirmdialog.js. Does this require a separate issue to be logged?