How to restore functionality after updating The Dude?

Question

System administration

Hello!
Version 4.х.х was on the server, it was rarely used and at one fine moment I decided to update it. Unloaded all copies of the program and installed the latest version.
Can't connect after installing The Dude 6.39.2:
connect failed 10061: Connection failed because the destination computer denied the connection request.
Today I logged in as admin, last event:
2017.06.09-11:51:53: User admin logged out from 127.0.0.1 via tcp
The server did not restart, I can only try at night.
What could go wrong? )

Answer 1

The implementation of the server on Dude 6.xx has been redone.
Offsite discussion:
Dude Server on Windows

Answer 2

The Dude. Practical monitoring.

Answer 3

As far as I know, there is no normal way to transfer the database from version 4 to version 6.