It shouldn't matter either way. The auto-login feature of GMarks stopped working a long time ago, when Google changed the URL for authentication and the add-in has never been updated. If you enter your information, it won't accomplish anything so don't bother.
Fortunately, GMarks doesn't need its own login. Visit the Google Bookmarks web page (
https://www.google.com/bookmarks/) and login from there if necessary. Then refresh GMarks.
If you accept the cookie from Google, GMarks will continue to work until the cookie expires - then you can do another login/refresh to renew the cookie. If you don't accept the cookie, or if you clear it, then you'll have to do this every time you start your browser.
-- David