What is the correct command please ??
I spent a long time trying different commands etc. As far as I know, there is only one way to fix it. I will attach the page which has the instructions on what to do. You must download an ISO file and put it on your USB drive. You CANNOT use the built-in reset, either keeping you personal files or wiping it clean. This won't work.
You must download. I'm a little busy the day before Christmas but perhaps someone else can give you a step by step off that page.