When you change your account password and want to Go to My Courses, in order to synchronize the new password to the elearning platform, you have to logout and log back into your account in order to generate a new session with your new password.
If you don't logout and log back into your account, you won't be able to participate to the courses because your session is registered with the old password. When you log back in, a new session is generated and you can click Go to My Courses.