Hi, I downloaded yED and imported a few 2 Cisco icon packets. Then created network diagram of my company and after saving it and then reopening menuts are gone, diagram is gone. I looked through all options but I don't know how to pull back all menuts and bars and my diagram. I spent 6+ hours on it...
Can you upload the GraphML file of your saved diagram here for inspection? Otherwise it is quite impossible to determine what the problem might be.
Please see How to upload files to yEd Q&A? for instructions on uploading files.