I installed a new disk and reinstalled the programs I was using before, including Context-lmtx
It is on lubuntu 18.04 on an old 32bit machine.

When I run from the console:
context sanstitre-2.tex
mtxrun          | unknown script 'context.lua' or 'mtx-context.lua'

When I run from TeXworks, I get only one line:
startup error : no format file given, quitting

So there is a step which didn't work.

What should I do?