After KDE 4.13 update weird network plasmoid problem

Hi,

Yesterday I installed the KDE 4.13 update on the machine of my girlfriend. Everything went smooth, though there’s one minor issue.
After every login the desktop shows a plasmoid saying that the network connection could not be established, but there’s nothing wrong with the network. It’s not the plasma-nm plasmoid complaining.
See the screenshot. I can only close the dialog by pressing ESC. I already tried figuring out the name of the plasmoid, but without success. Has anyone an idea? Thanks.

Well, if it’s a plasmoid, I would suggest the following:
Unlock the widgets (right-click on the desktop), then move the mouse over the plasmoid.
As soon as you touch it, a handle bar should appear.
Click on the settings icon (the wrench), or right-click on the plasmoid and choose “Settings”.

This should give you a clue what plasmoid that is I suppose.

The plasmoid is unclickable. I don’t even know if it’s one. The handle bar doesn’t appear as well. :\

Hm. TBH, I have never seen something like this, so I have absolutely no idea what it could be.

Another guess: right-click on the desktop and select “Default Desktop Settings”.
What have you configured there? Maybe something that needs an internet connection (f.e. “Picture of the day”)?
Try to select a simple picture as background. Does it go away?

Another thing: I have seen/heard about problems with the system tray plasmoid when hiding things.
Does it appear/disappear when you click on that up-arrow (just left of the clock) to show/hide symbols?

Since you suspected the plasma-nm plasmoid, I don’t see that in your screenshot. Is it activated? Try to deactivate it in the system tray’s settings (right-click on the up-arrow to reach them).
Are you actually using NetworkManager, or rather ifup?