Hello,
That's very bad

I had one similar report but was unable to reproduce this problem.
What was the version you updated from?
Is it standalone version or eclipse plugin?
Are there any errors in error log?
There is a file data-sources.xml in your workspace (USER_HOME/.dbeaver/PROJECT_NAME), defualt project name is "DBeaver". It contains descriptions of all connections.
Is thisfile present? Does it contain any information?
Note: If you'd try to start two instances of DBeaver at the same time then second instance will use not default workspace but will create new one in DBeaver installation directory - please make sure that previous DBeaver version isn't running. If it is then simply close both instances and start new version again.
Thanks for report