My b2evolution Version: 3.3.3

Hello,

I recently upgraded from v2 to v3 and all works well except from an error I receive when in the admin interface.

Error is displayed in the admin panel login dashboard page, on section: Updates from b2evolution.net

It states: Remote error: Connect error: Connection refused (111) (5)

I've attached a screenshot of what gets displayed below....

http://www.kpcsystems.nl/b2error.jpg

Now I searched this forum and haven't been able to find a solution for it.
I also disabled all plugins to check if this makes a difference, but it doesn't.

What can this be?

I also noticed that uploading a new plugin into the /plugin-directory doesn't display the uploaded new plugin in the admin panel.
I have no ability to install the/a new plugin from the admin panel as well.

Is this a security issue maybe?
Or a MySQL connectivity/security issues maybe?

Any information appreciated!

Thanks.