or
Anonymous
In this MWE

```tex
\documentclass{scrartcl}  

\usepackage[spanish, activeacute]{babel}   
\usepackage{unicode-math}  
\usepackage{hyperref}  

\begin{document}  
\section{A section}  
\begin{equation}  
  j =\sqrt{-1}  
\end{equation}  
\end{document}
```

there is a fatal error. However, if I comment `activeacute` or `\usepackage{hyperref}` or `\usepackage{unicode-math]` or I change the kind of document to article, for example, the error disappears. Any help? Thanks 
Top Answer
Skillmon
I did not test thoroughly whether all the features work, but it seems like loading `babel` after `unicode-math` fixes the issue at hand.

```tex
\documentclass{scrartcl}

\usepackage{unicode-math}
\usepackage[spanish, activeacute]{babel}
\usepackage{hyperref}

\begin{document}
\section{A section}
'a
\begin{equation}
  j =\sqrt{-1}
\end{equation}
\end{document}
```
Lualatex and unicode-math
Anonymous
Thanks for your interest.
Skillmon
@Anonymous Just found that there already is a related/duplicate issue in the bugtracker of `unicode-math`, therefore I didn't open another one. See: https://github.com/wspr/unicode-math/issues/462
Anonymous
But I think is a good idea report this problem to the maintainers of the unicode-math and babel packages. Can you do it? Thanks in advance.
Anonymous
@Skillmon In fact, I think the problem was activeacute as  Ulrike Fisher told me. I'm going to eliminate in my work. Thanks for your input .
Skillmon
@Anonymous did you also report this to the maintainers of those packages? If you didn't and don't want to, I'd do so.
Skillmon
@Anonymous Moving `babel` below `unicode-math` does work.
samcarter
@Anonymous To better understand your question, could you please add a small example why you need the `activeacute` option? Maybe there are other ways to achieve your desired output without it.