In my distribution, the MWE fails to compile:
\documentclass{article}
\usepackage[most]{tcolorbox}
\begin{document}
Test
\end{document}
with the error message:
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017)
(preloaded format=pdflatex) \write18 enabled. entering extended mode
(./bac_a_sable.tex LaTeX2e <2017-04-15 Babel <3.10 and hyphenation
patterns for 84 language(s) loaded.
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Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
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/usr/local/texlive/2017/texmf-dist/tex/latex/tcolorbox/tcolorbox.sty:2196:
I can't find file `tcbposter.code.tex'. <to be read again
\relax l.2196 ...expand\tcbuselibrary{\tcb@optionlist}}\x
tcbposter.code.texis missing. The question is why that file is absent if it should be on your system or why another file calls on it when it should not be on your system. Did you update any packages manually? – moewe Jun 28 '18 at 13:09tlmgr. Manual updates only cause trouble. – moewe Jun 28 '18 at 15:43tcolorbox.doc.poster.texin the folder/usr/local/texlive/2017/texmf-dist/tex/latex/tcolorbox... – Colas Jun 29 '18 at 13:47texhash: https://tex.stackexchange.com/q/21726/35864 – moewe Jun 30 '18 at 06:16