Erreur récurrente : ! Missing

! Missing $ inserted.
<inserted text>
$
l.41 ...ateriaux-quand-la-houle-contourne-le-port_
133017}

I've inserted a begin-math/end-math symbol since I think
you left one out. Proceed, with fingers crossed.
! Extra }, or forgotten $.
l.41 ...x-quand-la-houle-contourne-le-port_133017}

I've deleted a group-closing symbol because it seems to be
spurious, as in `$x}$'. But perhaps the } is legitimate and
you forgot something else, as in `\hbox{$x}'. In such cases
the way to recover is to insert both the forgotten and the
deleted material, e.g., by typing `I$}'.
! Missing $ inserted.
<inserted text>
$
l.43

I've inserted a begin-math/end-math symbol since I think
you left one out. Proceed, with fingers crossed.
! Missing } inserted.
<inserted text>
}
l.43
I've inserted something that you may have forgotten.
(See the <inserted text> above.)
With luck, this will get me unwedged. But if you
really didn't forget anything, try typing `2' now; then
my insertion and my current dilemma will both disappear.