I'm stuck at character selection. whenever I try to start the game an error occurs stating that "Onigiri has encountered a fatal error. A log of this error has been saved in (the folder where my onigiri game is)" and I am provided a site to send a copy of this, but the site isn't working.

Do you remember what area your character currently is? Certain areas either lag badly to the point of crashing, or if you're in a field that has the Kikuzou in it, you could also crash from that if your computer isn't practically NASA's.

As for the website, here's where you go if you have an issue; http://onigiri.cyberstep.com/help/faq/topic/game/6538?s=

And this is their support for reporting things; https://www.cyberstep.com/help/mailform