issues with footer content plugin

Dear WPMU,
actually I really wanted to solve it by myself but it is taking too much time.
I installed the "footer content" plugin.
I inserted this html Impressum

but it is directing me to an error page.”" target="_blank">””
I believe the link has been saved twice somewhere but I cant delete it....

could you pls help me out?!
I installed global footer content as well but I deactivated it.

- I deleted and installed footer content as well but nothing changed.