OK, thnx for the reply weefselkweekje,
Maybe I did something wrong this afternoon, but just now I copied the 1.12 version to the plugin-folder and put the code in the sidebar.php, and it worked!!!
Then I transferred the 1.13 version over it and it still works…
I can’t exactly remember, but I’m quiet sure I already done so this afternoon.
Anyway… problem solved!!