Hi,
First off, thanks a lot for Fusion360! I see great potential (although there are currently many issues on the Mac version and I can't see how you can actually require one to pay for a totally unfinished software).
An issue I'd like to report is that if you enter odd characters when loging in (e.g. !"#€%&/()=?><) the login window will be replaced with an HTML page with a redirect link which leads to an Internal Server Error. See the attaches screenshots. From here you have no navigation to return to the login, but to quit Fusion360 and try again. (You can actually use backspace to move backwards, but that's not really obvious) I believe the same thing occurs if you try to create an account this way.