I have now installed the new version of 0.7.26. Even before the old version 0.7.25 was installed. So I had downloaded the upgrade package from http://e107-german.de/news.php of German. Because we are a German community, and we English is not so powerful. I'm first to the problem, why did I open this Tread:
In the administration there is always a message when A new version of the e107 Content Management System available. Now have the new version and geupdated Nevertheless, the message does not disappear, even though everything now is currently up to date.
Don't worry. I saw the same thing. Its harmless. You're looking at cached information. It will disappear by it self. The information you are seeing is taken from e107.org whenever an (main) admin visits the admin part of the site. This information is cached and renewed every 24 hours.
A solution might be: Remember: when updating your site: flush your cache ! Admin => Cache => Emty cache. The file will be thrown away - no more message