I'm trying online activation for a used iPhone 6s that I was told by a Virgin Mobile tech support person was cleared for use with Virgin. I ordered a new SIM card from Virgin a couple days ago, and it arrived today, so I installed it and got onto the Virgin website and began the activation process. The activation pages didn't complain about my iPhone's IMEI number or the new SIM card's ICCID number, but the process hung at the "Choose your plan" page. No plans are displayed to choose from, and when I click on the page's "next" button, nothing happens. I tried twice in Chrome, and once in Safari, with the same result.
I got this solved by calling Virgin customer support (888-322-1122), where a tech rep explained that the "Choose your plan" page was hanging because I had an old AutoPay $5 a month discount plan from 2013, and apparently the web page was trying to display my existing plan to show me what I currently had, but it couldn't because Virgin dropped their $5 a month discount for AutoPay plans for new customers on August 29 2018. The rep switched activation to my iPhone 6s, and she was able to keep me on my AutoPay $5 discount plan too. She did all this very quickly, with no other issues getting in the way, so I'm grateful for her work.