Cannot access WP via MarsEdit-Editor

Hi,

in the past I have used a desktop-blogging-editor "MarsEdit" on my mac - long time ago I have used it to update my blog and in the meantime I have subscribed to WMPUDEV and deployed the dashboard on my WP.

Since then - I guess - the editor cannot connect with the blog anymore.

Does anybody know why and how to grant access again?

Thank you and kind regards,
Sascha