This website receives thousands of visitors everyday. By far the majority are able to login or create accounts without any problems.
Firstly, you do not need an account to use this website, such as to study courses or download lectures; everything on this website is available to anyone, anonymously, without restrictions of any kind. The sole benefit of having an account on this site is that it gives you access to the "Ask Instructor" feature, where you can ask questions of instructors.
Remember: only instructors can answer questions. Having an account does not allow you to answer questions.
The primary reason a few visitors have difficulty registering or logging in to the website is because their IP address (the address of the computer) is being flagged by our security system. There are only a few causes for this:
1. The visitor has repeatedly entered a mistaken username or password. Repeated failed login attempts causes the website to think the visitor is trying to hack into the site.
• Wait. The blocking feature will expire after half an hour and you can try to login again. Of course, you need to know the right username and password.
• If you forgot your password, use the "forgotten password" link and reset your password. Do you know the definition of crazy? It is to try the same thing again and again and expect a different result. If you don't know your password, reset it.
• If you cannot remember usernames and passwords, use a Password Manager.
2. The computer IP address has been flagged as being used for spam, hacking or other suspicious activity. If you are using a public computer (in a library, hotel, etc) or if you are behind some sort of layered security (such as a corporate or government building), these can trigger the security system. Note that our website is not the one who flags these addresses: our security system uses Project Honeypot, a worldwide collective effort to identify and block spammers, hackers, etc. The security system can also be triggered by attempts to download the website for offline reading.
REMEDY: Use a different computer, device, or network.
MORE DIFFICULT REMEDY: You can try setting up a VPN or work with Project Honeypot to clear your IP address.
3. The visitor created an account but did not verify it. Our website automatically sends new registrants a confirmation email. You must click the link in the email for your account to be made active. This is an automatic process, and it is always sent.
• Find the activation email and click the link.
• Make sure you entered the correct email address when creating the account.
• Make sure your email account will accept the registration email (some email security features will block it).
• Check your spam folder for the registration link.