Interesting thing. One person wrote me about a mistake I did 2 years ago. The correct command would be "fmtutil" and not "texhash"...
texconfig runs fmtutil automatically. That's why it worked that time.
I have learnt it later. And have re-learnt it today (I had forgotten) when this guy wrote me.
I'm sorry for my mistakes when I knew a little less than I know today... Specially when they make people loose time.