%% test-errors.tex
%% ===============
%% The errors of tcbpagefootnote.  Run with -interaction=nonstopmode and
%% select the case by \CASE:
%%
%%   pdflatex -interaction=nonstopmode -jobname=test-errors-float \
%%     "\def\CASE{float}\input test-errors"
%%
%% Cases and the error message to find in the log:
%%   float    "page footnote" with "float":
%%            "The key 'page footnote' cannot be used with 'float'."
%%   after    "after skip" given after "page footnote":
%%            "The 'after' code of this box no longer flushes the page
%%            footnotes."
%%   defined  the key "page footnote" is defined before the package is
%%            loaded:
%%            "The tcolorbox key 'page footnote' is already defined."
\ifdefined\CASE\else\def\CASE{float}\fi
\documentclass{article}
\def\TPFcase#1{\def\TPFtmp{#1}\ifx\TPFtmp\CASE}
\TPFcase{defined}
  \RequirePackage{tcolorbox}
  \tcbset{page footnote/.style={}}
\fi
\usepackage{tcbpagefootnote}
\begin{document}
\TPFcase{float}
  \begin{tcolorbox}[float, page footnote]
  A float box\footnote{A footnote.}.
  \end{tcolorbox}
\fi
\TPFcase{after}
  \begin{tcolorbox}[page footnote, after skip=1pt]
  A box\footnote{A footnote.}.
  \end{tcolorbox}
\fi
Text.
\end{document}