Fly by night

Crispin designed our website. He did an excellent job, but exactly 1 year to the date of the site going live, it stopped working. Error message: "There has been a critical error on this website" I have not been able to get hold of him since. He does not respond to messages or calls. We are unable to access the site ourselves and will now need to hire someone else to start from scratch. He forgets how small the world is...