Here is some advice from the help forum, thanks to forum member Naomi Price.
Try a different login procedure.These instructions seem to be solving the problem for most people. Please let me know if you still have problems after following these steps.
1. Login to Blogger using "www.blogger.com".2. Do not check "Remember me".
If that does not help, try again.1. Clear cache, cookies, and sessions (not just cache or cookies) - then restart the browser.2. Login to Blogger using "www.blogger.com".3. Do not check "Remember me".
Silvia