I am using the arrows.meta library to modify the arrow tips of my graphs. The problem is, that when I use the code below once, it works, but when I use it a second time, it does not. I tried it with and without the \usetikzlibrary{...} command in the second picture, I changed node names and so on.
I don't even want the exact same graph a second time, I just want to use the [-{Latex[...]}] arrow tips in another graph.
Error message:
Package pgf Error: Unknown arrow tip kind 'Latex'. \draw[-{Latex[.....
Minimum example:
\begin{figure}[H]
\begin{center}
\usetikzlibrary{arrows.meta}
\begin{tikzpicture}[align=center,node distance=3cm]
\footnotesize
\node [knoten,draw](a)[label=above:1] {$*$};
\node [knoten,draw](b)[below left of=*1, label=above:2] {$+$};
\draw [-{Latex[width=2mm,length=2mm]},red] (a.north east) .. controls +(up:2cm) and +(left:2cm) .. (b.south west);
\end{center}\end{figure}

arrows.metain the preamble, not somewhere in between – Mar 08 '18 at 09:30\usetikzlibrarybefore\begin{document}– percusse Mar 08 '18 at 09:30