# XeLaTeX plus (‘+’) sign undefined

I'm using XeLaTeX with specified fonts CMU and UbuntuMono

\usepackage{fontspec}
\usepackage{amsfonts}
\usepackage{unicode-math}

\setmainfont[Extension = .ttf, Path = ./../fonts/, UprightFont = *rm, ItalicFont = *it]{cmun}
\setmathfont[Extension = .ttf, Path = ./../fonts/]{cmunit}
\setmonofont[Extension = .ttf, Path = ./../fonts/, UprightFont = *-Roman, ItalicFont = *-Italic]{UbuntuMono}

However, anytime I'm trying to use any simple math symbol just like plus or equal sign in math mode, it throws error. For example:

./report.tex:190 Undefined control sequence.
<argument> (2+
1)\cdot (2\text {+}1)
l.190 \end{longtabu}

For line 127

$$\frac{1}{(2+1)\cdot(2\text{+}1)}\text{=}0{,}11$$

With ‘+’ sign specified as ‘\text{+}’ I getting no trouble except for innormal binary operator spacing.

I have no idea how can I fix it

• inside a tabular (of any kind) I don't see the reason to use math in . Use  instead.  would possibly work in a miniopage... but I can not see it (since you didn't provided a MWE :tex.meta.stackexchange.com/questions/228/…). Mar 29 '18 at 9:28
• Why would you set the math font to cmunit, which isn't a math font to begin with? The standard font used by unicode-math is Latin Modern Math, which blends nicely with CMUnicode. Mar 29 '18 at 15:48

Seems that you are using a math environment of the type $...$ inside a tabular (longtabu) environment.

Possibly you are not using it inside a minipage or somewhere that could be acceptable.

For example check this:

\documentclass{article}
\begin{document}
\begin{tabular}{cc}
$$F(x)+3$$ & %does work
%$g(x)+9$ Doesn't work
\begin{minipage}[b]{4cm}
$g(x)+9$ % Does work but... not reason for it
\end{minipage}
\\
z & 6
\end{tabular}
\end{document}

Reason: The  environment "says" to the compiler to place the math their own line, centered etc. But inside the tabular, if theri is not a minipage or something similar... there is no line to add... no center of line etc...

• I've replaced it with $$\frac{1}{(2+1)\cdot(2+1)}=0{,}11$$ but still having same problem. I also tryed to use XITS Math font but getting same result for operators like ‘+’ and ‘=’. \cdot/\times works correctly. Mar 29 '18 at 9:46
• Please read the link of the comment on your answer and provide a MWE. Nobody can help you otherwise. I just found an obvious mistake. This was the only I (or anyone) could do . You can Edit your post providing a MWE that demonstrates the problem and I am sure you will be helped in minutes... Mar 29 '18 at 9:53