I had some reasonable experiences with Udemy, but recently I bought a Splunk power user course by , course delivered, then disappeared. I tried to get paypal to contact them, but Paypal surprisingly wasn't much help. Udemy help center is a joke. Just a set of links to nothing that helps. Turns out, my course was halted. It's in my learning section, but the videos are not playing. I am never buying courses from Udemy again. That one star is for no customer service and my inability to get help to get a refund.