Most hotel wifi networks require opening a browser to connect. Once you open it, the first page you go to is redirected. Because a lot of sites default to HTTPS, that redirect is detected as a MITM by the browser, and prevents you from moving on. http://neverssl.com/ is an easy way to get to the portal without an issue.
As noted on NeverSSL:
> [...] it [...] means that if you're relying on poorly-behaved wifi networks, it can be hard to get online. Secure browsers and websites using https make it impossible for those wifi networks to send you to a login or payment page. Basically, those networks can't tap into your connection just like attackers can't. Modern browsers are so good that they can remember when a website supports encryption and even if you type in the website name, they'll use https.
