Is it possible to import or upgrade somehow our current configuration (devices, maps, links) from Dude v3.6 to Dude v4.0beta1?

I just installed 4.0 beta1 over top of 3.6 and everything came across.
Maybe install 3.6, import then upgrade?

as always make a copy of the dude folder on your working system before messing with it.

Right now I have a Dude v3.6. I tried to stop Dude sevice and than close Dude program, than install v4.0beta1 over v3.6. Stated the Dude service, than tried to connect to localhost as admin, but failed. Then I tried to reset all settings and after successfull connection I tried to import old backup from v3.6. It shows something like "Uploading..." and nothing happens.

As I understand upgrade from v3.6 to v4.0beta1 should work smoothly. So I'll make another try and let you know about results.

Don't stop the server, let the installation program figure that out.

Local host will not connect on 127.0.0.1. Change to the actual address of the local host.

Well, I tried to install v4.0beta1 over v3.6 with stopped and not stopped Dude service and everytime I failed. I tried to import my v3.6 export file to v4.0beta1 in many different ways and everytime after importing I couldn't connect to this service with any username to any host. Only one thing helps, completely reset settings. But it's unacceptable for me, beacuse I don't want to recreate Network map with hundreds of hosts manually.

I am curious do you have your 3.6 installation working? Hope you at least have not lost everything...

There is probably something wrong in the XML. Maybe you can you look through it and find the issue? Download an XML editor and just take a gander. A decent XML should at least highlight the tags and values so you can quickly scan it.

They do look at problems with the dude. Maybe you can zip up your XML and send it to them and ask them find the trouble?
Email support first and see what they think...

Before 4beta they needed a tool that would find problems in the export but since they spent so much time converting to database i am sure they just never had a chance to make one.

Now that it is a database at least they are easier to repair and harder to break.