texlive2017 non funziona più [risolto]

Salve. Ecco il mwe:

`
\documentclass[12pt]{article}
\usepackage{latexsym}

\begin{document}

\begin{equation}
\int_{a}^{b} f(x)\text{d} x=0.123456789
\end{equation}

\end{document}

Il testo non si compila. Ecco quanto dice il terminale:

[code]
Running `LaTeX' on `prova14c' with “pdflatex -file-line-error -interaction=nonstopmode “\input” “prova14c.tex”''
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017/W32TeX) (preloaded format=pdflatex)
restricted \write18 enabled.
entering extended mode
LaTeX2e <2017-04-15>
Babel <3.10> and hyphenation patterns for 84 language(s) loaded.
(./prova14c.tex (c:/texlive/2017/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(c:/texlive/2017/texmf-dist/tex/latex/base/size12.clo))
(c:/texlive/2017/texmf-dist/tex/latex/base/latexsym.sty) (./prova14c.aux)
(c:/texlive/2017/texmf-dist/tex/latex/base/ulasy.fd)
./prova14c.tex:7: Undefined control sequence.
l.7 \int_{a}^{b} f(x)\text
{d} x=0.123456789
[1{c:/texlive/2017/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./prova14c.aux) )
(see the transcript file for additional information)
Output written on prova14c.pdf (1 page, 34203 bytes).
Transcript written on prova14c.log.

TeX Output exited abnormally with code 1 at Fri Jun 16 18:13:03
`

[/code]

Cosa devo correggere?

Grazie. Ciao,

davide