Rules / Build

Package pgfkeys Error: I do not know the key '…' — TikZ/PGF error

TikZ stopped on an unknown option, a missing semicolon, or an undefined node.

Fix

Fix the option spelling, end paths with ;, or load the needed TikZ library.

Example

Reproduced on TeX Live 2026 by CI · pdflatex · corpus/tikz-unknown-key

Unknown TikZ option

Fails: main.tex
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
  \draw[colour=red] (0,0) -- (1,1);
\end{tikzpicture}
\end{document}
Fixed
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
  \draw[color=red] (0,0) -- (1,1);
\end{tikzpicture}
\end{document}
What TeX prints in main.log
! Package pgfkeys Error: I do not know the key '/tikz/colour', to which you passed 'red', and I am going to ignore it. Perhaps you misspelled it.

See the pgfkeys package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.5   \draw[colour=red]
                        (0,0) -- (1,1);
This error message was generated by an \errmessage
command, so I can't give any explicit help.
Pretend that you're Hercule Poirot: Examine all clues,
and deduce the truth by order and method.