For a fifth year straight, running, the number one technical support issue at Giza is browser-specific issues. In other words, something in the user's browser (a plugin, an add-on, a toolbar, etc) prevents correct operation of the site within that browser. The fix is either a) switch browsers (Firefox, Chrome, Safari), or b) try opening a private/incognito window and using the site that way, or c) troubleshoot the browser issue which is beyond the scope of our support, since it's different for any given individual. If it works in one browser and not another, that localizes the problem to your browser.
What we find most commonly is that it may work in Firefox or Chrome or Safari for 98% of individuals but fail for 2% because, for that 2%, the browser installation is not the same. It has been altered by something specific to that user's computer system. In other words, it works for everyone else in Firefox but not for YOU in Firefox. Or Chrome. Or Safari. Etc.
If you've had difficulty accessing, viewing, or interacting with some portion of Giza, the first and most common fix is to try the same thing in a different browser. The aforementioned three browsers are the most stable options. Given how common it is to customize browsers these days, intentionally or unintentionally, knowingly or unknowingly, this will resolve nearly all issues that aren't related to billing.
For other issues, check the FAQ and, if your issue is not covered or resolved, open a support ticket.