I dont want to repeat the advice you will have seen from your own searches. What have you found so far? Was it anything like this:
"Error 01 is a brew unit fault. usually coffee grounds clogging things up. Before you get it repaired, try to get it going. Remove tray and try and clean up inside, use a brush, torch and hoover. If you are able try and run the cleaning program, use double the dose of tablets, and run it twice. Cost nothing so worth a try."
I assume that did no good but I cant see anything else.
I assume you HAVE tried searching