The problem can be corrected by upgrading the affected package to version 1.7.6-1ubuntu0.1 (mozilla-locale-de-at), 1.7.6-2ubuntu0.1 (mozilla-locale-da) and 2:1.7.6-1ubuntu0.1 (mozilla-locale-fr). In general, a standard system upgrade is sufficient to effect the necessary changes.
Details follow:
USN-155-3 and USN-186-3 updated the version of the mozilla-browser package to fix several vulnerabilities. It was determined that this rendered the Dansk, German, and French locale packages uninstallable since their dependencies were too specific. The updated locale packages work with all present and future versions of mozilla-browser.